WO2016067065A1

WO2016067065A1 - Insul-cryo online insulation system

Info

Publication number: WO2016067065A1
Application number: PCT/IB2014/002251
Authority: WO
Inventors: Jean SKAF
Original assignee: Insulco Emirates
Priority date: 2014-10-29
Filing date: 2014-10-29
Publication date: 2016-05-06

Abstract

With the advent of industrialization, the use of cryogenic insulation in the liquefaction and transportation of natural gas, the developments of superconductors, electronic devices and medical techniques require much higher thermal insulation efficiency than usual industrial and building insulations. The present invention relates to an INSUL-CRYO Online Insulation System for improving the characteristic of cryogenic piping to vessels, equipment heat exchangers, pipes and all fittings when the plant is in operational conditions within a temperature range of +26 degree Celsius to -185 degree Celsius.

Description

INSUL-CRYO Online Insulation System

TECHNICAL FIELD

[001 ] The present invention relates to an insulation system suitable for cryogenic applications; a system of modules for insulating a component; a method of manufacture of the insulation modules; and a method of installation of the insulation modules.

BACKGROUND OF THE INVENTION

[002] It is known in the prior art that the purpose of insulation is to reduce the impact of ambient environmental conditions on desired temperature within insulated environment by reducing the heat transfer driving force between the ambient and insulated environment. Some of the known cryogenic insulations are described in US Application No. 09/830,398, US Application No. 12/752,514 and PCT Application No. PCT/EP2011/07391 1. While these insulation systems fulfil their respective objectives, none of the prior art describes the unique INSUL-CRYO Online Insulation System described hereunder.

SUMMARY OF THE INVENTION

[003] In view of the foregoing disadvantages inherent in the prior art regarding known type of cryogenic insulation, the present invention provides an INSUL-CRYO Online Insulation System comprising of Preformed Polyisocyanrate Foam (PIR), in-situ moulded / dispensed Polyurethane Foam (PUF).

[004] The installation involve wrapping of an insulating material around the component, for example panel constructions, which are adhered or otherwise secured to the component. The insulation operation involves the location and fastening of layer(s) of insulating materials, which may be of the same or different nature with the component to be insulated. In large scale industrial context, the objectives of insulation include conserving a desired temperature range within that component. Within the industrial plant, achievement of this objective is associated with the cost efficiency as heating and cooling costs may be substantial and may be reduced by effective insulation to prevent heat loss or gain from the insulated component. The insulation process is time consuming and requires a great deal of organization to competently and cost-effectively carry out the installation.

[005] Cryogenic plants in conventional use for example in gas processing operate at temperature well below the freezing point of water. Therefore, insulation barriers in cryogenic plants are subject to high thermal shock or stress making development of suitable insulators very difficult. By Way of example, the temperature difference between the interior of the insulated component and the ambient environment may be of the order of 200 degree Celsius such that expansion behavior may be encountered in outer portions of the insulation and contraction behavior may be encountered in inner portions of the insulation. All these problems mean that specific insulation techniques and materials are required in cryogenic applications. As with other insulation applications, major costs are encountered in the installation operation as various insulation materials must be fabricated on site to meet the requirements of the application. The present invention illustrates the supply and application of external cryogenic insulation to vessels, equipment heat exchangers, pipes and all fittings when the plant is operational conditions within a temperature range of +26 degree Celsius to -185 degree Celsius.

[006] It is the primary objective of the present invention to provide a cryogenic insulation system comprising of Preformed Polyisocyanrate Foam (PIR), in-situ moulded / dispensed Polyurethane Foam (PUF). [007] It is another object of the invention to provide an INSUL-CRYO Online Insulation System which is accurate in its performance during the operational condition of the plant.

[008] Other objects and advantages will become apparent from the following description and appended claims.

DETAILED DESCRIPTION

[009] In the following description, certain specific elements are provided in order to understand the various disclosed embodiments. However, a person skilled in the art who read the disclosure and the claims will realize that the disclosed embodiments can be practiced with or without one or more of these specific details or with other elements without deviating from the scope of the disclosure.

[010] Reference will be now made in detail to the various embodiments of the disclosure. Wherever possible, the same reference will be used throughout the description to refer to the same or like embodiments.

[01 1] The present invention relates to an INSUL-CRYO Online Insulation System for improving the characteristic of cryogenic piping to vessels, equipment heat exchangers, pipes and all fittings when the plant is operational conditions within a temperature range of +26 degree Celsius to -185 degree Celsius which comprises of Preformed Polyisocyanrate Foam (PIR), in-situ moulded / dispensed Polyurethane Foam (PUF).

[012] The material used as inner layer of insulation is Preformed Polyisocyanrate Foam (PIR) which is preformed and complies with the following specification:

• Density not less than 50 kg/m3, in accordance with ASTM D- 1622-63

• Closed cell content not less than 95%

• Thermal conductivity shall be approximately 31.5 W/M2

• Compressive strength at 10% deformation not less than 2.5 kg/m2 in any random direction at 20°C, in accordance with A STM- 1621-73

• Surface spread of flame in accordance with BS 476 Part 7, Class 1, UL-94 ASTM D 3014 Self- extinguishing.

• Residual weight of sample having a minimum of 90% isocyanurates when tested in accordance with ASTM D-3014-76. [013] The material used as outer layer of insulation is in-situ moulded/dispensed Polyurethane Foam (PUF) complies with the following specification:

• Self-extinguishing fire properties in accordance with ASTM D-1692 (10/10 SE)

• Density after moulding shall be 45 kg/m3, ± 5%, in accordance with ASTM D-1622

• The free rise density shall be 28 ( ± 2) kg/m3, to ensure good compaction of the foam and good homogeneity due to high compression rate

• Minimum percentage of closed cells 90% (percent) per ASTM D-2856

• The leachable halides content shall not exceed 30 ppm.

[014] Another component used in the insulation material is pre-formed spacers which shall be of rigid PIR with the following minimum properties:

• The spacers shall consist of fully monolithic moulded (180°) half pipe sections with a minimum density of 50 kg/m3, designed to form compartments for the in-situ moulding operation.

• The foam shall have a fire-resistive property as defined in ASTM D- 1692 (10/10 SE): self- extinguishing.

• Minimum percentage of closed cells 90% per ASTM D-2856

• Thermal conductivity at 20 °C mean temperature per ASTM C- 177, measured on 25 mm thick foam cut on both sides and aged at 21 °C for 180 days shall be no greater than0.025 W/m.K.

• The leachable halides content shall not exceed 90 ppm.

[015] In order to fix the PIR-Foam rings and bars to the vapor barrier a quick setting adhesive shall be used and it will be a two component adhesive with high strength thermo setting urethane containing no flammable solvents. The adhesive is preferred for use with rigid polyurethane insulation:

Table 1 :

[016] A moisture sealer has to be installed on the inside of the PIR foam and in all the joints between segments and pipe sections when fixing the first layer of PIR foam the cold surface of the pipe, equipment, vessel while the plant is operating.

[017] In the INSUL-CRYO Online Insulation, metal cladding is used as the weather-proof jacketing to all piping and equipment to both cryogenic/cold services. The specification will be as follows:

Table 2:

[018] Banding to secure insulation materials shall be stainless steel to in accordance with the following specification:

Table 3:

Banding to secure the weather-proof jacketing shall be stainless steel to in accordance with the following specification:

Table 4:

[019] The tape used to secure the PIR shall be pressure sensitive glass fiber which is reinforced to a minimum width of 19mm.

[020] The process of INSUL-CRYO Online Insulation starts by removing existing cladding & damaged insulation in such a quantity that all primary and secondary vapor barriers shall be applied in the same day. After removing the old insulation and before installing the new PIR the pipe shall be scraped clean of all ice, rust and old adhesives. Insulation shall be installed in a minimum length of 1 meter. An expansion and contraction joint will be installed at the end of each meter Insulation shall be installed in 2 halves up to 12 inch diameter above this 4 pieces are provided up to 24" and beyond this the panels will be cut suit. The inner layer of insulation shall be applied with a coat of cryogel moisture sealant on the inside and all the joints. The inner layer of insulation shall be secured by means of pressure sensitive tapes. To join the pieces of inner layer insulation adhesive sealant shall be used. The insulation shall be covered with vapor barrier in 1 meter width with and overlap of 75mm and all the joints shall be sealed.

[021] In order to provide the proper hardening of PUF material a moulded panel made from galvanised steel in a thick 0.8mm up to 8 inch and 1.00mm above the mould will be secured by means SS bands. Holes will be predrilled in the top of mould (for horizontal piping) and outer vapor barrier to pour the PUF material.

[022] The PUF material needs to be poured to all the voids through the holes till foam appears at venting holes.

[023] For vertical pipes the PUF mixture shall be injected through the holes located below the top PIR ring.

[024] After setting the foam the mould shall be removed and filling holes of the vapor barrier shall be sealed with patches of vapor barrier.

[025] The outer layer of insulation and vapor barrier shall be jacketed by sheet metal cladding with longitudinal and circumferential overlap. The longitudinal overlaps shall be placed with proper water shed. The jacketing shall be secured by means of SS bands and seals.

[026] All the arrangements shall be same as adjacent pipe insulation. Before and after the fitting an expansion/contraction joints will be installed. On the bends a PIR ring will be installed in the center to keep the proper thickness. Metal jacketing shall be riveted together to form two halves before installation At the end of straight pipe vapor barrier will be sealed directly on the pipe by means of sealing tape Install PIR rigid sections & vapor barrier as inner layer same as mentioned for pipe insulation. The PIR rings will be installed on the top of adjacent insulation. PUF can be injected through the holes in the mould & vapor barrier as prescribed for pipe insulation. After setting mould shall be removed and filler holes in the vapor barrier shall be sealed. New prefabricated metal box will be installed after over the flexible polyfoam strips. The inner layer of insulation shall be applied after the surface is wiped clean & dry. All the joints shall be sealed with sealant and inner layer shall be secured by means of SS bands and seals. Expansion shall be provided at the end of each meter, on horizontal vessels it will be vertical on vertical vessels it will be horizontal. On the horizontal equipment PIR rings shall be installed circumferentially every 850mm and bars shall be fitted horizontal at 500mm. Thickness of rings shall be varying in size from 50mm to 100mm. Installation of vapor barrier, mould and injection same as prescribed for pipes. After the setting of PUF seal the holes and replace the mould with new metal jacketing.

[027] The thickness of outer layer PUF insulation between vapor barrier and sheet metal moulded jacketing shall be maintained by means of PIR support spacers. Piping up to 8 inch diameter one PIR ring shall be installed approx. at every 900mm. & above 8" one ring shall be spaced at approx. 500mm apart. The PIR ring will be secured with pressure sensitive tape & fixed with quick setting adhesive. Above the PIR ring the vapor barrier shall be installed and all the longitudinal and circumferential joints shall be sealed.

[028] It is to be appreciated that the optimum dimensional relationships for the parts of the invention to include variations in size, materials, shape, form, function and manner of operation, assembly and use are deemed readily apparent and obvious to a person skilled in the art and all equivalent variations to the ones described in the specification are intended to be encompassed by the present invention.

[029] Therefore, it needs to be appreciated that the aforementioned description is just an illustration of the principles of the invention. Since numerous modifications, variations, improvements and changes will readily occur to those skilled in the art, it is not considered to limit the invention to the exact described format of the invention or its manufacturing and accordingly all suitable modifications and equivalents may be falling within the scope of the invention.

Claims

We claim,

1. A method of improving insulation characteristics of a cryogenic piping to vessels, equipment heat exchangers, pipes and the like, comprising of Preformed Polyisocyanrate Foam (PIR), in-situ moulded / dispensed Polyurethane Foam (PUF).

2. A method according to claim 1 wherein the cryogenic insulation is online, that is insulation is completed when the plant is in operational condition.

3. The INSUL-CRYO Online Insulation System according to claim 1 and 2 wherein the temperature range of the operational plant will be of +26 degree Celsius to -185 degree Celsius.

4. The method of claims 1 and 2 wherein the pipe volume comprises a straight section and an elbow section.

5. The method of claims 1, 2 and 4 wherein the insulation volume extends around the pipe volume for the entire length of the straight section and the elbow section.

6. The INSUL-CRYO Online Insulation System using Preformed Polyisocyanrate Foam (PIR) having density not less than 50kg.m3, closed cell content not less than 95%, thermal conductivity be 31.5W/M2, compressive strength be 10% deformation, having surface spread of flame and residual weight of sample being at a minimum of 90% isocyanurates.

7. The INSUL-CRYO Online Insulation System using in-situ moulded / dispensed Polyurethane Foam (PUF) having self-extinguishing fire properties, density after moulding be 45kg/m3, ± 5%, free density be 28 (±2) kg/m3, minimum percentage of closed cells be 90% and the leachable halides content not to exceed 30ppm.

8. An INSUL-CRYO Online Insulation System as described herein.