Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
  • D21H13/36—Inorganic fibres or flakes
  • D21H13/38—Inorganic fibres or flakes siliceous
  • D21H13/40—Inorganic fibres or flakes siliceous vitreous, e.g. mineral wool, glass fibres
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
  • C04B26/02—Macromolecular compounds
  • C04B26/28—Polysaccharides or derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
  • C04B26/02—Macromolecular compounds
  • C04B26/28—Polysaccharides or derivatives thereof
  • C04B26/285—Cellulose or derivatives thereof
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L59/00—Thermal insulation in general
  • F16L59/02—Shape or form of insulating materials, with or without coverings integral with the insulating materials
  • F16L59/028—Compositions for or methods of fixing a thermally insulating material
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249924—Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
  • Y10T428/249928—Fiber embedded in a ceramic, glass, or carbon matrix

Definitions

• This invention relates to improved thermal-insulating material for use at temperatures in excess of 500F., and more particularly to improved thermal-insulating material of the type containing mineral wool and an organic binder and which can be particularly utilized as a thermal-insulation pipe covering.
• Pipe coverings of the prior art have generally been provided as either loosely integrated fibrous or granular material, such as mineral wool, glass wool and the like, or flexible felts in mat or ribbon form, such as wool or hair felt, provided with a wrapping material to hold the bulk in place when wrapped about the pipe; or in fabricated molded or cast rigid forms such as of various asbestos, mineral wool and the like compositions held together in substantially rigid form by a ceramic inorganic binder.
• a ceramic inorganic binder In this latter form of pipe insulation, the cost of ceramic inorganic binders contributes to making the product too expensive for extensive utilization as a pipe insulation material.
• one object and advantage of the present invention is the provision of fibrous insulation material, for use at temperatures above about 500E, which insulation material contains organic binders and other organic constituents, yet which material does not emit objectionable smoke, odors and the like.
• Another object of this invention is the provision of thermal pipe insulation in substantially rigid form comprising a mineral wool product of the type having mineral fibers bonded by an organic binder, without accompanying emission in use of noxious vapors, objectionable smoke, or punking.
• Still another object of this invention is the provision of heat-insulating mineral wool products of the type having mineral fibers bonded by an organic binder, wherein the product may be utilized as a thermal insulation at temperatures between about 500 to about 1,000F. without substantial emission of noxious vapors, objectionable smokeor punking.
• the activated charcoal may be any of the carbon, char or charcoal produced by destructive distillation of wood, peat, lignite, nut shells, bones, vegetable or carbonaceous matter activated as is usually achieved by heating to temperatures of about 800900C. with steam or carbon dioxide to bring about a porous particle structure.
• the wood-based or coal-based activated charcoal is preferred, and it does not appear to make any difference which is used; and thus the carbon content of the activated charcoal may vary widely.
• the activated charcoal may be of widely varying density, as generally available from 0.08 to about 0.5, and structural hardness, and neither characteristic appears to be of any particular importance to the present usage.
• the porosity of the particles does make a difference in the performance for this use, and it is preferred that higher porosities be utilized as generally exhibited by larger sized particles.
• particle size of about by 325 US. Standard mesh sieve particles have been found satisfactory, and particles of about 50 by 325 mesh are especially preferred. While particles of somewhat greater or lesser size would be suitable for the use herein, it has been found that particles of greatly larger or smaller size are not satisfactory.
• the amount of the activated charcoal to be utilized will generally depend upon the amount of organic binder and other organic constituents in the mineral wool product and will be present in an amount that is from about one-half of to equal to the amount of organic constituents of the product. Thus, in general it is preferred that amounts of about /2 to about 5 percent by weight of the total product be utilized based upon preferred mineral wool products containing generally about 3-10 percent organic binder and other organic constituents such as a wax. Accordingly, if greater or lesser amounts of organic constituents are present in the mineral wool product, the quantity of activated charcoal to be incorporated will vary directly therewith.
• the precise composition of the particular mineral wool insulation product employed is not critical to the invention provided that they may contain generally from about 3 to about even 30 percent by weight of cellulosic binder or other organic constituents.
• suitable mineral wool insulation product for use in the present invention may contain from about 5 to about percent by weight of mineral wool and from about 3 to about 30 percent by weight of cellulosic binder or other organic binder constituents.
• the mineral wool product is generally formed by water casting or water felting an aqueous slurry of mineral wool and the other ingredients, although other means may be used.
• the mineral wool used in the products of the present invention comprise fibers formed in well known and conventional employed mineral wool production processes from blast furnace slag and the like.
• the precise composition of the particular mineral wool fibers utilized is not critical to the invention.
• a preferred form of such binder is a non-fibrous water-activated cellulosic binder prepared by forming a slurry or furnish of cellulosic material, preferably of unbleached waste kraft paper. The slurry is then gelatinized by passing it through a series of refining and gelatinizing steps to obtain a suitable freeness. It has been found that a preferred water-activated cellulosic binder of this type for forming the mineral wool product has a Schopper-Riegler freeness of less than 100, and preferably less than 90.
• organic constituents entering into the formulation of the products of the present invention may come from optional ingredients added to obtain superior processing and product characteristics for the basic mineral wool product, as by the inclusion of a wax or wax emulsion to serve as a sizing to stabilize the material in high-humidity storage conditions.
• the wax may be employed in amounts up to about 2 percent by weight, although preferably comprising from about 0.25 to about 1 percent.
• the wax utilized is usually in the form of an emulsion or dispersion, and may be one or more of several varieties, such as, for example, microcrystalline, refined paraffin, petroleum, synthetic waxes, etc.
• a particularly preferred emulsion would comprise about 50 percent asphalt and about percent wax, by weight.
• a fusible ceramic clay preferably non-swelling and having a high proportion of silica and alumina, such as fire clay, ball clay or the like present in an amount at least equal to about the amount of organic binder, so as to serve adequately as a binderreplacement at elevated temperatures.
• a fusible ceramic clay preferably non-swelling and having a high proportion of silica and alumina, such as fire clay, ball clay or the like present in an amount at least equal to about the amount of organic binder, so as to serve adequately as a binderreplacement at elevated temperatures.
• compositions may optionally contain certain additives for optimum properties and processing characteristics.
• alum for sizing and perlite fines or clay pellets to adjust product density may be included in the formulation, depending upon the product characteristics desired.
• Some perlite may be included where higher hardness levels are desired in the product, and thus preferably about 10-20 percent of perlite may be employed, generally utilizing the well-known thermally expanded product which is available in a variety of mesh sizes.
• boric acid or sodium borate may be used in amounts up to about 6 percent by weight, and preferably from about 2 to 5 percent to impart even better fire resistance, which materials generally do not provide any impact with reference to inhibiting smoking and odors.
• a convenient and meaningful test evaluation of smoke emission is by means of a small pot test" utilizing about 6 inch by 6-7 inch by 1 inch thick samples of the material to be evaluated.
• a Hoskins furnace or equivalent pot furnace having a 5 inch diameter and 5 inch furnace depth is equipped with a Wheelco controller set for 1,000F.
• a thermocouple is centered at the very top of the furnace and covered by a previously fired piece of ceramic material to cover the whole furnace surface plus about an extra 1 inch area, and the furnace is heated up to l,O00F. When the l,OOOF. temperature is reached, the prefired piece of material is quickly taken off the furnace and the test sample put in its place during a time of a couple of seconds.
• a high-temperature thermometer is placed on top of the test sample to measure the outside surface temperature of the test sample and a timer is started.
• the controller maintains the temperature at 1,000F. on the underside of the test sample, as measured by the thermocouple.
• the outside surface temperature as measured by the thermometer begins to rise as the sample piece is heated by the furnace. There is generally a jump in the outside surface temperature due to the burning of the organics, and after the organic constituents of the test sample have burned away the outside surface temperature thermometer reading drops; and this peaking of the outside surface temperature is used as a measurement of the end of the test.
• the test time is about 19-24 minutes depending upon the quantity of organics in the test sample.
• a black background is placed around the furnace and test sample to increase visibility of smoke. The time of any smoking interval is noted during the test.
• a 1,000F. hot pipe test apparatus has been utilized to provide an accurate simulation of severe field service conditions for pipe insulation samples.
• a 57 /2 inch long section of 6 inch inside diameter and about 7 inch outside diameter steel pipe is provided, on the inside of the pipe, with radiant heating elements spaced equidistantly to provide uniform heating the length of the pipe.
• the heat ing elements such as a Chromalox commercial heating element, are spaced down the center of the inside of the pipe and supported by pieces of refractory material, Spaced behind the pipe is a sheet metal background painted black and illuminated by spotlights to aid in 0bserving visible smoke.
• test samples to be evaluated are placed around the pipe, covering a three-foot section of the pipe, and the heating elements are activated to start the test.
• the insulation is then observed for visible smoke and odor while the temperature, measured by a series of thermocouples, is brought up to l,O0OF. and maintained there for about 22 minutes for one-inch samples. Samples thicker than one inch were tested for about 60-90 minutes.
• Exemplary examples of the above formulations were submitted to the hot pipe test and evaluated to simulate severe field service conditions.
• the samples containing the activated charcoal of '80 by 325 mesh produced a very small amount of smoke for a few minutes and were judged acceptable.
• the control comparison sample not including the activated charcoal produced at least 20 times more smoke.
• an equivalent formulation utilizing the 50 by 325 mesh activated charcoal in the same amount did not smoke at all while the pipe temperature was increased to l,OOOF.' and did not punk during this time nor give off any detectable odors.
• An improved heat-insulating mineral wool product including about 40-65 percent by weight of mineral wool, from about 3 to about 8 percent by weight of water-activated cellulosic binder, about /2 percent of wax-asphalt emulsion; and from about 1 to about 5 percent by weight of activated charcoal particles.
• a thermal insulating pipe insulation material of non-smoking characteristics comprising from about 40 to about percent of mineral wool; from about 1 to about 10 percent or organic constituents, principally cellulosic binder; and from about V2 to about 5 percent of activated charcoal particles.
• a method of making a non-smoking thermal insulating material suitable for use as a covering for pipe comprising the steps of adding to an aqueous slurry of mineral wool fibers and organic binder an amount of activated charcoal of about /2 to about equal the amount of organic constituents; forming a sheet therefrom; and drying said sheet.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Inorganic Chemistry (AREA)
• Thermal Insulation (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23783374

Family Applications (1)

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Cited By (3)

Citations (4)

• 1974
  • 1974-03-08 US US449222A patent/US3909347A/en not_active Expired - Lifetime
• 1975
  • 1975-02-19 CA CA220,422A patent/CA1034708A/fr not_active Expired

Patent Citations (4)

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