US2325940A - Method and apparatus for producing mineral wool - Google Patents

Description

H. T. COSS Aug. 3, 1943.

METHOD AND APPARATUS FOR PRODUCING MINERAL WOOL Filed July 21, 1937 INVENTOR.

Harold T. Coss Patented Aug. 3, 1943 METHOD AND APPARATUS FO R PRODUCING MINERAL WOOL- Harold T. Coss, Somerville, N. J., asslgnor to Johns-Manville Corporation, New York, N. Y., a corporation of New York Application July 21, 1937, Serial No. 154,866

8 Claims.

This invention relates to a method and apparatus for producing mineral wool. More particularly, it relates to a method of collecting mineral wool fibers and an apparatus for carryit out the method.

It is an object of this invention to provide a method of producing mineral wool which is free from solid particles commonly known as shot.

It is a further object of this invention to provide an apparatus for making shot free mineral wool and which is capable of operating for long periods without failure.

Other objects and advantages, if not specifically pointed out, will be apparent to those skilled in the art from the following detailed description of what are now considered to be the preferred embodiments of the invention.

Referring to the drawing:

Fig, 1 is a side elevational view, partly in section, of an apparatus constructed in accordance with the present invention, and

Fig. 2 is a fragmentary, horizontal, sectional view taken substantially on the plane indicated by line 22 of Fig. 1, and looking in the direction of the arrows.

It has been attempted heretofore to produce mineral wool which is relatively free from the solid particles commonly known in the industry, as shot, by fiberizing molten raw material at one point and carrying the fibers and attendant shot in suspension in a moving and confined stream of gas to a distant point for collection of the fibers. During the travel of the suspended particles and fibers, the heavier particles tend t separate away from the air borne fibers, so that when the distant point is reached the fibers and shot are to a large extent segregated. The fibers are then collected from the suspending medium by a suitable collecting means and the shot is deflected into a shot trap. While this method has been successful, it has been attended with serious operating troubles due to a tendency for the shot and, in some cases, for masses of tangled fibers to settle along the path of the stream and rapidly build up into mounds of sufiicient proportions to obstruct the stream confining means and impede and, in time, completely prevent progress of the stream.

It has been found that the foregoing operat-. ing troubles can be eliminated by continuously removing the particles and fibers which settle out of the moving stream, so that there is no opportunity for the hot fibers and shot to accumulate and form an obstruction.

Referring to Fig. 1, the means for melting the raw material is shown as a conventional cupola 2. It is to be understood that numerous other types of furnaces may be employed without departing from the spirit of the invention, and the cupola 2 has been selected merely for the purpose of explanation. The stream of molten material 4 fiowingfrom the cupola 2 is formed into fibers by any conventional means, such, for example, as a conventional jet or nozzle 6 which discharges a blast of steam or other gas moving at a high velocity against the stream of molten material 4 to divide the stream into fine fibers, and, to a lesser extent, into shot. The fibers and shot are suspended by the fiberizing gas, when a steam or air blast fiberizing means is used, and carried into a blow tube indicated generally at B. Other types of fiberizing devices, such as centrifugal machines,.may be employed instead of the jet 6 if such is desired.

The blow tube 8 directs the fibers to a suitable fiber collecting apparatus In. The fiber collecting apparatus I0 is shown diagrammatically since it may takemany different forms, but the preferred form is disclosed in patent pt Hermann F. Vieweg, No. 2,110,280, issued March The fiber collecting apparatus will, in any event, generally comprise a felting member such as the foraminous drum I2 which is rotatably positioned over the end H of the blow tube 8 and supported and rotated by any suitable means. The end I4 of the blow tube is shaped to conform to the cylindrical outline of the drum I2, or to conform to the configuration of the felting member, regardless of the type employed, in order to avoid leakage between the tube and felting member. Suitable gaskets may be used if desired to insure tightness at this point.

A suction box IE, which may be in the form of a hood, is positioned within the foraminous drum l2 and extends over the area of the drum which is exposed to the interior of the blow tube 8. The drum I2 is revolved by any suitable prime mover (not shown) and the suspended fibers are drawn by the action of the vacuum within the hood l6 onto the drum and felted thereby into a bat or web H! which is suitably removed from the drum l2 and further treated and disposed of as desired.

The fiber collecting means 10 includes a shot trap'20 which comprises a wall 22 positioned so as to deflect the shot into the trap and a door 24 biased into closed position by a weight W. When there is a sufiicient accumulation of material in the trap to overbalance the weight W,

the door 28 will automatically open and discharge the same and then close under the action of the weight W.

The bottom of the blow tube 8 is provided with an opening which may vary in length but will usually extend from the shot trap towards the cupola 2 to a point .near the open end of the blow tube. Angle irons 28 are riveted or otherwise suitably secured along the sides of the opening with their bottom fianges extending substantially horizontally. An endless conveyor 28 is formed by passing an endless belt 38 over rollers 32 which are Journaled in suitable supports and positioned so as to place the upper run 34 of the conveyor over the opening formed in the bottom of the blow tube. The conveyor 28 is driven by any suitable motor 36 by means of a belt, chain or other type of connector.

The conveyor 28 is preferably positioned so that the upper run 34 discharges settled solid matter and entangled fibers into the shot trap 20.

A scraper 38, which may be V-shaped, is suitably supported in position to act upon the conveyor to remove any particles which might adhere too tightly to the belt to fall into the trap 28. The scraper 38 may be disposed at any desired point.

During the operation of the apparatus, the suspended fibers and shot are carried into and through the blow tube 8. During the passage of the suspension through the tube 8, the lighter fibers do not settle to the same extent as the heavier shot. This results in the fibers and shot being segregated as the suspension approaches the collecting device to. Because of this segregation the light fibers are drawn onto the foraminous drum I2, and the shot strikes the wall 22 of the shot trap and is deflected into the trap. During the passage of the suspension through the blow tube 8, any particles, whether shot or entangled fibers, which strike against thebottom of the tube 8 are not permitted to remain within the tube and form a nucleus for an accumulation which would soon reach sufiicient proportions to completely clog the tube 8, but are removed by the movement of the upper run 34 of the conveyor and deposited within the shot trap 20, or are scraped from the felt by the scraper 38.

The upper run 34 of the belt 30 is held up tightly against the bottom flanges of the angle irons 26 by the pressure of the atmosphere be cause of the reduced pressure within the tube 8 caused by the suction within the box l6. This forms an effective seal between the upper run 34 of the belt 30 and the casing which forms the blow tube 8.

If desired, the belt 30 may' be perforated or made of some form of mesh material so as to allow for the entrance of a moderate amount of air through the belt. Air which so enters through the belt will tend to aise the light fibers away from the belt without afiecting the solid particles to the same extent, and thereby further segregate the fibers from the solid particles.

Other types of movable members may be substituted for the belt 30 if desired, but the belt is the simplest and most practical generally.

The foregoing details have been given for the purpose of explanation and not limitation, since many changes and modifications may be made in the apparatus disclosed, and other apparatus may be used to perform the method without departing from the spirit of the invention.

Having described the invention, I claim:

1. In an apparatus for producing mineral wool comprising means for melting raw material and forming fibers therefrom which are suspended in a moving gaseous stream, and means for collecting the fibers so formed; a blow tube for receiving the suspension. of fibers and directing the same to the collecting means, the blow tube comprising a hollow casing for confining the fiber stream at the top and sides and provided with an opening along its under side, and a relativehr impervious member movable toward said collecting means closingthe said opening and forming a movable bottom for the casing.

2. In an apparatus for producing mineral wool comprising means for melting raw material and forming the same into discrete fibers suspended in a gaseous medium, and means for collecting and felting the fibers in the form of a mat or web; means for receiving the suspension of fibres and directing the same to the collecting and felting means, the last named means comprising a hollow casing for receiving and confining the fiber stream at the top and sides and provided with an opening along its under side, and a relatively impervious endless belt conveyor, including an upper substantially horizontal run, positioned so that said upper run closes the 3. In an apparatus for producing mineral wool comprising a furnace for melting raw material, means for converting the molten material into fibers and denser solid particles suspended in a moving gaseous stream, means for collecting the fibers from the gaseous stream and felting them into a mat or web, and a trap for the dense solid particles adjacent the fiber collecting means; means for receiving the stream of fibers and solid particles and directing the same to the collecting means and trap, respectively, the last named means comprising a hollow casing for receiving and confining the said stream at the top and sides and provided with an opening along its under side, and an endless substantially particle impervious belt conveyor positioned so that its upper run closes the opening in the casing and collects solid particles which settle out of the stream and conveys the same to the said trap.

4. In the method of making mineral wool comprising melting suitable raw material, converting the molten material into fibers and denser solid particles and suspending the fibers and particles in a substantially horizontally moving gaseous stream, the steps of confining the stream of suspended fibers and particles for a sufllcient distance to enable the solid particles to settle away from the lighter fibers, separately collecting the fibers and solid particles, and continuously removing from the path of the confined stream and in the direction of movement of the stream all particles and fibers which settle out of the stream prior to collection of the fibers.

5. In an apparatus for producing mineral wool comprising means for melting raw material. and forming the same into discrete fibres and denser particles suspended in a moving gaseous stream, fibre collecting means, and particle receiving means adjacent said fibre collecting means; means confining the stream and directing the stream to the collecting means, and movable means forming a wall of the confining means positioned to convey the denser particles settling out of the stream in the direction of movement of the stream to said particle receiving means.

6. In an apparatus for producing mineral wool comprising means for melting raw material and opening in the casing.

forming the same into discrete fibres and denser particles suspended in a. moving gaseous stream, means for collecting the fibres from the gaseous stream, and particle receiving means; means comprising a hollow casing for directing the stream to the collecting means, and a substantially horizontal conveyor associated with said hollow casing and forming a wall thereof and positioned to collect the denser particles which settle out of the stream and convey them in the direction of movement of the stream to said receiving means.

7. In an apparatus for producing mineral wool comprising means for melting raw material and forming the same into discrete fibres and denser particles suspended in a moving gaseous stream, means for collecting the fibres from the gaseous stream, and particle receiving means; means comprising a hollow casing for directing the stream to the collecting means, an endless conveyor associated with said hollow casing and including an upper reach positioned to collect the denser particles which settle out of the stream and convey them to said receiving means, and cleaning means operating on the outer surface of the lower reach of the conveyor.

8. In an apparatus for producing mineral wool comprising means for melting raw material and forming the same into discrete fibres carried in a moving gaseous stream, and vacuum collecting and felting means for the fibres; a blow tube for directing said stream to the collecting and felting means comprising a hollow casing having an opening in its under face, and an endless conveyor including an upper reach positioned to closely underlie said tube and to close said opening, whereby said reach is pressed closely against said tube by the suction created by said vacuum collecting and felting means.

HAROLD T. COSS.

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