US2633062A - Method of removing water from fibrous masses - Google Patents

Description

March 31, 1953 J. E. GASTON 2,633,052

METHOD OF REMOVING WATER FROM FIBROUS MASSES Filed Sept. 50, 1947 Patented Mar. 31, 1953 METHOI) F REMOVING WATER FROM FIBROUS MASSES Jack'E..Gaston, Manheim Township, Lancaster County, Pa., assignor to Armstrong Cork Company, Lancaster, Pa a corporation of Pennsylvania Application septembcr so, 1947, Serial No. 777,038

' 6 Claims.

My invention relates to a method of removing water from fibrou's'masses and is concerned more particularly with a method of removing water from mats in the production of heat insulation materials.

the manufacture of insulation blocks from a slurryof mineralwool'fibers, paper pulp fibers, and "a binder such as asphalt, one common practice'is to chargethe fibrous material and binder into'a vat with'a large quantity of water and effect an intermingling of the 'mineralwool fibers, paper pulp fibers, and binder. The slurry thus formed is then deposited into a mold having a foraminoustbottom, andwater is drained therefrom. 'I'he massis then compressed to the desired thicknessand the moldedmass is discharged from the'mold. "In the'initial slurry the fiber and'binder content may be'equivalent to about 6 to 7% of thetotal weight of the slurry; and in the manufacture of blocks 37" x 37 x i, the total weight of the slurry may be in the neighborhood of 900 to 950 pounds. Subsequent to forming and compressing, and at the time of discharge ofthe mass fromthe mold, the mass may contain 190 to 2 20 pounds of water representing 75 to 80% of the total weight of the mass.

The formed mats customarily are stacked on cars with the planes of the upper surface of the mats lying substantially horizontally. The cars are then carried through an oven where drying of the mats isefiected. Subsequent'to the pressing operation, substantially 'no moisture drains from the mass and heating is necessary in order to evaporate the water. The cost of drying is substantial, particularly where'from 75 to 80% of the total weight of the'bl'ock is water.

7 It is a'nobject of my invention to provide a method by which substantial quantities of water may be'removed' from the block after compres-' sion and prior to drying in the heating chamber.

Another object of my invention is to'provide an economical and convenientmethod of removing'water from formed and compressed blocks prior to heating and drying.

A further object of my invention is to provide a method of removing substantialouantities 'of water from fibrous products without substantial increase the density thereof resulting from water removal. In order that my invention may be readily understood, I will describe thesamein' conjunction with the attached drawing, in which the figure.

is a perspective view sh'owing typical'apparatus useful in carrying outmy'method. I

-I have discovered that fibrous mats containing substantial quantities of water suei xa a block compressing by positioning the blocks with the planes of the fiat faces thereof disposed at an angle'between 15 and 90 with respect to the horizontal. The fiat faces referred to are the faces which lie parallel to the plane of the pressing surface. In the 37" x 37" x 5" mat, the fiat faces would be the faces having dimensions 37"): 37". V As a typi'calexample, a block 37" x 37" x 5" after compression was weighed and'found to have a weight of 267 pounds. The block was placed on a drying screen and was inclined with the upper face disposed at'an angle of about 57 with respect to the horizontal. Inone-half hour, 31 pounds of water poured from the edge of the block. At the end of one hour, 50.5 pounds of water had drained from the block. In two hours, 69 pounds had been removed; in three hours, 77 pounds; in four hours, 83 pounds; and in twenty hours, 98 pounds. The block at the end of the draining periodweighed 169 pounds. In order to compare this with drying by merely'placing the block on a drying screen with the plane of the upper surface of the block substantially horizontal, a block of similar size and weight subsequent to compression was placed for drainage in the position mentioned, and after twenty hours, only six pounds of water had drained and evaporated from the block.

The average weight of blocks of the type here under consideration subsequent to compression,

- but prior ,to drying or draining, is about 270 pounds and the completely dried blocks have an average weight of aboutfiopounds. Therefore, the average weight of water in the blocks after forming and compression is about 210 pounds. With a large number, of blocks treated, I have found the following average efficiencies to prevail:

. Pounds of Percent Time at 57 Angle Water Water 3 Removed Removed 3o 14 24 31 as so as 95 45 The angle'of repos'e of the blocks may vary be: tween 15 and with respect to the horizontal.

In the manufacture of the product referred to above formed of mineral wool, paper pulp, and asphalt emulsion, the drying pallet screen is of a diamond mesh opening; and it has been found that the frictional engagement between the wet block and the pallet screen will hold the block against sliding with respect to the screen up to an angle of about 60. With an angle greater than 60, it may be necessary to clamp the block to the drying pallet in order to prevent slipping. I have found that, by providing an edge support for the blocks against which they may rest while in an inclined position, slumping of the products will not occur and water drainage may be effected conveniently. Any additional support which may be necessary to hold the blocks against slippage or slumping may be provided. The particular mechanism employed for carrying out my method is not important and constitutes no part of the present invention.

I have illustrated in the drawing which accompanies this application a simple arrangement for carrying out the method. In this equipment the drying cart is indicated at 2 and includes a truck ,3 having wheels 4 mounted thereon. The truck is partitioned so as to receive twelve blocks 5, each of which is placed upon a drying pallet screen 6. A baffie I extends from the truck 3 to the top of the carriage and is effective for preventing water, which drains from the right-hand stack of blocks 5, from reaching the blocks in the left-hand stack. The cart 2 is arranged so as to perform the dual function of supporting the blocks in an inclined position during draining and in a substantially horizontal position during their travel through the drying oven in the manner described above.

A draining rack 8 is provided, which is pivoted at 9, and includes an open base It) and an upright support Ii. A leg 12 is provided for holding the rack 8 in an inclined position.

In the operation of the mechanism, the blocks subsequent to compression are removed from the molds and placed on the screen pallets 6, which are then loaded in stacked position upon the cart 2. The card 2 is then rolled to a position overlying the rack B with the support l2 removed and the rack in lowered position. A hoist I3 is then brought into position with its lifting hook ii in engagement with the eye 15 of the rack B. The hoist is then operated to elevate the rack into an inclined position, and the support I2 is positioned to hold the rack in the proper inclined position. In this position water drains from the blocks and is carried off by a suitable drain.

While I have used a mineral wool insulating block as a typical example of a material which may be operated upon in the practice of my method, my invention is not limited thereto. The term mineral wool is used herein in its usual sense to include rock wool, slag wool, glass wool, and other similar wools of mineral origin. The angle of repose will depend, to some extent at least, upon the type of material being operated upon, the nature of the screen pallet, the weight of the blocks, and other variable factors. If there is a tendency for the blocks to slip and slide on' and it is, therefore, necessary to correlate the cost of storing the blocks in an inclined position with the cost of removing water by heat drying. For most purposes, it generally will be found that mass production will not permit storage for periods greater than about two hours without the cost of storage, due to the large storage area required, outweighing the cost of removal of water by heating. Accordingly, for most purposes, drainage will be effected for about two hours or less, and the blocks will then be disposed in a drying oven for removal of substantially all of the remaining water. Where adequate space is available, drainage for periods up to twenty hours or more may be employed.

By my invention, I have provided a simple method which, startlingly, is effective for removing water from molded and compressed masses of fibrous material in large quantities far in excess of the quantities removable by maintaining the masses "with their fiat faces substantially horizontal. Since the cost of drying in a heated oven is almost directly proportional to the quantity of water contained in the mass to be dried, large savings are effected by the practice of the present invention.

By my process very substantial quantities of water may be removed from the mass under treatment without any measurable reduction in thickness of the product or concomitant increase in the density of the dried product. This is a very important factor in the manufacture of insulation materials, where an increase in density results in a decrease in insulating efficiency.

While I have illustrated and described a preferred embodiment of my invention, it will be understood that the same may be otherwise embodied and practiced within the scope of the followin claims.

I claim:

1. In a method of drying fibrous masses, the steps comprising forming to shape a slurry of mineral wool fibers and water, draining water from the slurry, expressing additional water from the mass by applying pressure thereto to reduce the mass to a mat of a desired thickness, said mat holding a substantial quantity of water, substantially none of which will flow from the mat while the mat is in a horizontal position, thereafter maintaining the compressed mat with the plane of the upper surface thereof lying at an angle between about 15 and about with respect to the horizontal to cause a substantial additional quantity of water to flow by gravity from the mat without materially aifecting the thickness orfinal density of the dried mat, and subsequently heating the mat while disposed in a substantially horizontal position to dry the same.

2. In a method of drying fibrous masses in the manufacture of porous insulation material, the steps comprising forming a slurry of mineral wool fibers in water, depositing the slurry upon a foraminous surface and draining water from the slurry, applying pressure to the mass to express additional water therefrom to reduce the mass to a mat of a desired thickness, said mat holding a substantial quantity of water, substantially none of which will flow from the mat while the mat is in a horizontal position, maintaining the compressed mat with the plane of the upper surface thereof lying atan angle with respect to the horizontal to cause a substantial additional quantity of water to fiow by gravity from the mat without materially affecting the thickness or final density of the dried mat, and thereafter applying heat to the mat while disposed in a substantially horizontal position to dry the same.

3. In a method of drying fibrous masses in the formation of insulation products, the steps comprising depositing a slurry of mineral wool fibers in water upon a foraminous forming surface, applying pressure to the mass to reduce the same to a thickness which will provide a desired density in the insulation product when dry, said mass in compressed condition containing substantial quantities of water which will not flow therefrom with the mass maintained in a substantially horizontal position, maintaining the compressed mass with the plane of the upper surface thereof lying at a substantial angle with respect to the horizontal to cause a substantial quantity of water to flow by gravity from the mass without materially affecting the density of the final product when dry, and subsequently heating the mass while disposed in a substantially horizontal position to finally dry the same.

4. In a method of drying fibrous masses in the formation of insulation products, the steps comprising depositing a slurry of mineral Wool fibers in water upon a foraminous forming surface, applying pressure to the mass to reduce the same to a block having a thickness which will provide a desired density in the insulation product when dry, said thickness being substantially less than the other dimensions of the block, positioning the block with its fiat faces disposed at an angle between about 15 and 90 with respect to the horizontal and maintaining the block at an angle with respect to the horizontal until a substantialquantity of water in excess of that which would fiow from the mass if maintained in a horizontal position has been caused to flow by gravity from the mass, and thereafter heating the mass while disposed in a substantially horizontal position to dry the same.

5. In a method of drying fibrous masses in the formation of insulation products from a slurry of mineral wool fibers and a binder of asphalt emulsion or the like, the steps comprising depositing the slurry of fibers, binder, and water in a mold against a foraminous forming surface, draining water from the mass, thereafter applying pressure to the massto reduce the same to a thickness which will provide a desired density in the insulation product when dry, removing substantial additional quantities of water from the mass without materially affecting the density of the insulation product when dry by disposing the formed and compressed mass on a supporting surface with the support lying at an angle between 15 and 90 with respect to the horizontal,

at which inclination substantial quantities of water will drain from the mass, and thereafter heating the mass while disposed in a substantially horizontal position to dry the same.

6. In a method of drying fibrous masses in the manufacture of porous insulation material, the steps comprising: depositing a slurry of mineral wool fibers in water upon a foraminous surface within a mold; draining water from the slurry by gravity flow; applying pressure to the mass to express additional water therefrom and reduce the mass to a mat of desired thickness, said compressed mat containing a substantial quantity of water, in the order of to of the total Weight of the mat, substantially none of which will flow from the mat while the mat is disposed in a substantially horizontal position; transferrin the mat from a horizontal position to a position in which the plane of the upper surface of the mat lies at an angle between about 15 and with respect to the horizontal to cause at least 30% of said contained water to fiow by gravity from the mat Without materially affecting the density of the final mat when dry; and subsequently heating the mat while disposed in a substantially horizontal position to dry the same.

JACK E. GASTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Practical Treatise on the Manufacture of Paper in A11 Its Branches, by Hoffman (1873),

page 328.

Paper Making Thru Eighteen Centuries, by Hunter (1930), pages 112, 127 and 137.

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