Cryogenic storage container

• US 4,055,268 A
• Filed: 11/18/1975
• Issued: 10/25/1977
• Est. Priority Date: 11/18/1975
• Status: Expired due to Term

• Current Assignee: Harsco Corporation
• Original Assignee: Union Carbide Corporation (Dow, Inc.)
• Inventors: Barthel, Alfred
• Primary Examiner(s): Bell, James J.
• Application Number:
  US05/633,087
• Time in Patent Office: 707 Days
• Field of Search: 220/9 C, 220/9 D, 220/9 LG, 220/14, 220/9 M, 428/285, 428/287, 428/296, 428/298, 428/302, 428/458, 428/461
• US Class Current: 220/560.12
• CPC Class Codes: B32B 1/00 Layered products having a non-planar shape
• CPC Class Codes: B32B 2262/0253 Polyolefin fibres vinyl or acrylic copolymers B32B2262/0223 or B32B2262/0246
• CPC Class Codes: B32B 2262/0276 Polyester fibres
• CPC Class Codes: B32B 2307/7242 Non-permeable
• CPC Class Codes: B32B 2439/00 Containers; Receptacles closures therefor B32B2435/00
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: F17C 13/001 Thermal insulation specially adapted for cryogenic vessels vessels not under pressure with insulation F17C3/02; thermal insulation in general F16L59/00
• CPC Class Codes: F17C 2203/018 by attachment at the neck
• CPC Class Codes: F17C 3/08 by vacuum spaces, e.g. Dewar flask for household use A47J41/02
• CPC Class Codes: Y10T 428/31692 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 442/626 Microfiber is synthetic polymer
• CPC Class Codes: Y10T 442/681 Spun-bonded nonwoven fabric

Abstract

A double walled cryogenic storage container with a vacuum space containing multi-layer insulation comprising thin radiation layers separated by permanently precompressed sheets comprising fibers having 3-40 microns effective diameter in stacked crossing relationship and at least 1% of the fibers being heat softenable and heat bonded together at cross points without external binder.

Claims

1. A container for storing materials at low temperatures comprising an inner vessel for holding such material;

a larger outer gas-tight casing having rigid self-supporting walls around said inner vessel of such size to form an intervening evacuated load-free space at an absolute pressure less than about 0.5 micron mercury, said space containing multi-layered thermal insulation comprising thin flexible sheet radiation barriers being supported by and in alternating relation with low conductive fibrous sheet layers in the permanently pre-compacted form weighing less than 2 grams/ft² and being comprised of fibers having 3-40 microns effective diameter and an intrinsic thermal conductivity of less than 0.2 BTU/hr-ft² -F/ft, said fibers being arranged in overlaying crossing relationship in planes parallel to the sheet surface with at least 1% (by number) of the fibers being heat softenable and heat self-bonded directly to each other at some of the cross-points without external binder, and said fibrous sheet layers undulating within the spacing between adjacent radiation shields over a transverse distance substantially wider than its thickness, contacting first one shield than the other facing shield.

2. A container according to claim 1 wherein the fibrous sheet layers are spun bonded.

3. A container according to claim 1 wherein the fibers are polypropylene.

4. A container according to claim 1 wherein the effective diameter of the fibers is less than 30 microns.

5. A container according to claim 1 wherein the effective diameter of the fibers is 10 to 30 microns.

6. A container according to claim 1 wherein the fibrous sheet layers weigh between 1.1 and 2 grams/ft.² and the area of fiber self-bonding comprises less than 20% of the sheet surface.

7. A container according to claim 1 wherein the fibers are polyester.

8. A container according to claim 1 wherein the fibers are polyester having effective diameter of 10 to 30 microns, and the fibrous sheet layers are spun bonded.

9. A container according to claim 1 wherein the fibers are polypropylene having effective diameter of 10 to 30 microns, and the fibrous sheet layers are spun bonded.