US2808929A

US2808929A - Cleaning mineral wool or rock wool

Info

Publication number: US2808929A
Application number: US268429A
Authority: US
Inventors: Emery J Fisher
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-01-26
Filing date: 1952-01-26
Publication date: 1957-10-08
Anticipated expiration: 1974-10-08

Description

Oct. 8, 1957 FISHER 2,808,929

CLEANING MINERAL WOOL OR ROCK WOOL Filed Jan. 26, 1952 2 Sheets-Sheet 1 IN V EN TOR.

4 [may J/Za/zef:

MQVMWW Oct. 8, 1957 FISHER 2,808,929

CLE'ANING' MINERAL WOOL OR ROCK WOOL Filed Jan. 26, 1952 2 Sheets-Sheet 2 INVENTOR.

E/72673] Ji /26f:

United sates Patent 2,808,929 CLEANING MINERAL woonoa noon wool.

Emery J. Fisher, Chicago, Ill. Application January 26,1952, Serial No. 263,429

1 Claim. (0.209 46) My invention relates to a process and-apparatus for cleaning commercial mineral wool and rock Wool so as to freeand'remove therefrom the hard, non-fibrous particles ranging in size from fine sand up to large nuggets which become enmeshed in mineral wool and rock woolduring the course of manufacture.

Commercial mineral wool and rock'wool is in the form or" small wads or pellets of the wool fibers which havea characteristic tendency to bunch or cling together in clumps. Throughout a mass of such rock Wool or mineral wool wads will be found hard foreign particles which range in size from fine sand or grit up to large nuggets or cinders. The very fine sand is derived mainly from thefracturing or powdering of the individual fibers making up the mineral wool or rock wool. Inaddition to such fine sand? there will be an appreciable quantity of small hard bodies in the form of solidified nodules or granul'es'of the molten slag or rock from which the wool is formed, such particles having a size in the order of pinheads. I n'.';addition to these fine foreign .bodies, there will be larger hard pieces of rock, slag and. cokehaving irregular shapes and i'anging'in size up to as much as an inch or more inthe longest direction. I i Commercial mineral wool androck wool contain such inclusions of hard foreign particles inherently as a result of the methods by which these products are manufactured. When mineral wool or rock wool is produced with equipment maintained in the, best of condition and properlyoperated there will be a smaller amount of such hard foreign particles in the commercial'product than where the producing machinery is clogged and in poor adjustment. and the operators are unskilled or careless. Under these latter conditions the commercial product will contain a'much larger proportion of the hard bodies. Large quantities of mineral wool and rock wool are used for insulation purposes. For example, large quantities of mineral wool and rock wool are used for blown in type insulationwhich is installed by special equip ment including feeders and'pneumatic conveyors. Mineral wool and rock wool are also used in another process of installing insulation which is'known as the .sprayedon process and which is described, for example, in Patents Nos. 1,718,507, 1,888,841 and 2,179,679 I, to Wenzel et al. In the sprayed-on process either mineral wool or' rock wool is often blended with another insulating material such as asbestos fiber and then this blended mixture is pneumatically conveyed to the spray gun from which it is blown onto the'wall or. ceiling surface while'rece'iving a coating of. an adhesive from the gun. The various pieces of power-driven equipment used in'handling mineral wool and rock wool insulation such as star-Whegltype feeders, proportioning devices, etc. have moving parts which are designed. 'to.close tolerance-for efiicient operation. Agreat deal of'difiiculty has beenencount'ered in handling commercial mineral wool and rock wool in such equipment dueto the inclu- The sand is highly abrasive and causes rapid-wear of the closely fitting parts. The larger nuggets or lumps causefrequent jamming resulting in damaged equipment, burned-out motors and a great deal of loss in.,time through shutdown. When one of the devices handling mineral-wool'orrock wool becomes jammed because of a cinder or nugget it is usually very difficult-tolocate theha-rd body in the wads of mineral W001 0fi100k" wool, as

the case may be, and it is usually necessary to completely clean.out the jammed machines in order to correct the stoppage .Sometimes theforces involved are so great that the larger nuggets or cinders are actually drivencoma pletely through'the sheet metal housings of the equipment. -.I-t.isnot uncommon practice-to have two or three extra pieces of mineral wool and rock wool handling equipmenton an insulating job in order to keep just one piece of equipment available and operatingfull time.

In addition to the jamming and rapid wearing prob lems referred to above, the fine sand particles cause another difliculty in the pneumatic conveying equipment which (often is very troublesome. Inpassing the rock wool or mineral woo-l through the conduit of a pneumatic conveyor, there is a tendency for electrostatic'charges'to be built up on the interior wall of the conduit, especially when the humidity is high. While the wads of'mineral wool or rock wool themselves do not account, for much ilfiiculty in' thismespect, the fine sandy particles asso ciated with the wads cause a considerable amount of this type of diflicultyyand result in eitherpoor, feeding or complete clogging of the conduitsor hoses; Reduction of the fine particle content eliminates this particular dif ficulty to a very large extent.

", T-he commercial producersof rockwool andmineral wool: are acquainted with the above and otherproblems' gether and tend to adhere firmly to any'object which does not have a polished surface. Accordingly, the inclusions of hard foreign bodies tend to remain tenaciously enmeshed in the wads and they are not easily loosened and freed therefrom. Because of the delicate nature of mineral wool and rock wool fibers, precluding applica tionof pressure and rough treatment, and the tenacious manner in which the hardforeign bodies are stuckf to and in the wads of wool, commercial cleaning of mineral wooland rock Wool has not been a mercial operation heretofore. g

. In accordance with my present invention I pro'videi-a process and apparatus wherein and whereby commercial mineral wool and rock wool may be completely freed of thehard foreign bodies in all sizesranging from'the fine sand up to the large size nuggets or clinker's, efiicientlyand.cheaply,'without altering or destroying the desirable an'd characteristic physical properties of the wool, and with'practically no degradation of. the wool productsint'o useless sand or grit. In accordance 'with my. invention the clumps or bunches of mineral wool or rock wool wads with their inclusions of hard foreign particles are gently shaken .or separated. into the individual wads or smaller clumps of only two or three wads and these are spread out in a wide. stream withthe wads being continuously tossed and, bounced in a gentle manner so as to divide the clumps into individual wads and shake the hard parpractical or com ticles loose therefrom. The fine particles of sandy texture are then separated out by passage through a screen with fine openings while the thin, spread-out stream of the separated wool wads and large particles and nuggets are fed into a rising air column wherein the wads of mineral wool or rock wool are lifted or carried off with the air current while the hard particles fall out. By making certain modifications and innovations I have found it possible to carry out my mineral wool and rock wool cleaning process on a basically old and well-known piece of equipment, long and widely used forcleaning a very difierent type of material in. an entirely different manner, namely, a grain or seed cleaner. 1

The object of my invention, broadly stated, is the provision of a process and apparatus for efficiently and economically cleaning mineral wool and'rock wo'ol so as to separate out the hard, non-fibrous, foreign particles inherently included therein and ranging in size from fine sand up to large nuggets and 'clinkers.

An important object of the invention is the provision of a novel process and apparatus for cleaning mineral wool or rock wool Without altering the physical properties thereof wherein commercial mineral or rock wool is fed into the apparatus and the clumps of the wool wads are gently opened up and dispersed, separated into smaller clumps or individual wads and the hard foreign particles are shaken looseand freed therefrom, while theentiremass is being spread out into a thin stream of bouncing material passing down an incline, the sandy hard particles being removed through a fine screen having small openings and with the wool wads and larger nuggets being introduced by gravity or a slight negative pressure into an air column of such velocity that the wads of mineral wool are carried off in the air stream while the solid particles fallout.

Another important object of the invention isa method following detailed description thereof taken in connection with the accompanying drawings, wherein:

Fig. 1 is a diagrammatic view illustrating the process of cleaning mineral wool or rock wool in accordance with the present invention using the machine shown in the remaining figures of the drawings;

Fig. 2 is a longitudinal vertical sectional view through one form of machine that may be used for cleaning the mineral wool or rock wool in accordance with the invention;

Fig. 3 is an enlarged fragmentary sectional view taken on line 3-3 of Fig. 2; V

Fig. 4 is a transverse sectional view taken on line 44 of Fig. 2; and I Fig. 5 is a detail elevational view taken on line 5--5 of Fig. 3 showing the sprocket drive mechanism for operating the moving elements in the hopper portion of the machine.

In its over-all general construction the machine shown in Figs. 2 through 5 corresponds to seed and grain cleaning machines of the type disclosed in Patent No. 814,918, for example. However, the machine of Patent No. 814,918 and seed and grain cleaning machines disclosed in the prior art cannot be used to accomplish the purpose and object of the present invention since certain critical modifications and innovations must first be made therein because of the basic difference in the materials being processed in the machines and basic differences in the cleaning processes carried out therein. 7

The cleaning machine comprises a suitable framing structure of known type and construction which is indicated generally at 5. The machine comprises four main operating parts or sub-assemblies, namely: a feed hopper of cleaning commercial mineral wool and rock wool so 7 as 'to separate hard foreign inclusions therefrom which comprises discharging the commercial products onto the upper end'of a downwardly inclined, shaking or vibrating screen having openings therein considerably larger than the averagesize of the individual wads of wool, catching the 'wool wads and hard foreign particlesfalling through the upper screen on a lower screen which is also inclined and shakingfand having openings considerablyfiner than the average size of the wool wads, with the fine sandy hard particles being separated through this lower screen, and discharging 'thewool and freed hard foreign bodies of larger size from the lower'end of the bottom screen at a neutral or slightly negative pressure into a rising'colunin of air'having an upward'velocitysuch that only the wads of wool rise and are carried off while the hard foreign particles fall out.

Another important object of the invention is apparatus for cleaning commercial grade mineral or rockwool so as to separate out the associated hard foreign particles which comprises a set of at least two superposed screens having means attached thereto for imparting a sharp shaking or vibrating action thereto,- the upper screen having openings considerably larger than the average size of the individual wads of wool-and the lower screen having openings considerably smaller than theaveragewad size,

and'an upstanding stackfor conducting a rising air column, the stack having a slot-shaped side inlet opening lnto which the bottom end of the lower screen empties, such inlet opening having a vertical width considerably greater than the. average wad diameter but sufiicientlyj small to prevent'any outflow 'of air from the column when the air column is passing through the stack' witha veloc ty which will carry off the wads of wool while allowing the'hard foreign particlesto'fall out.

obvious andwill in partappearhereinafter. a

For a more complete understanding of the nature" and scope of the invention, reference may'n'ow be had to the assembly, the shaker screen assembly, the'blower unit and the separating column. These operating units are indicated generally in the drawings by the

reference numerals

6, 7, 8 and 10, respectively. The hopper 6 comprises a housing ll mounted on the top of: the frame 5 adjacent the front end thereof and extending across the width of the machine as shown in Fig. 3. 'Thehopper 6 is provided with an upper agitator paddle wheel 12 mounted on a shaft 13 journaled in opposite ends of the hopper 11 and provided on one end with a drive sprocket 14. Be-

neath the paddle wheel 12 is a group of three

smaller agitators

15, 16 and 17 located above a larger agitator 18 of the same type positioned in the bottom of the hopper 11. The

agitators

15,16, 17 and 18, as shown in Fig. 3, each 7 comprises a pair of longitudinal rods 1919 extending Certain other-objects oftheinventionj will in part be f between end fixtures 99 which are mounted on supporting shafts journaled at their opposite ends in the ends of the hopper 11. The four agitators are provided with

sprockets

20, 21, 22 and 23, respectively, as shownin Fig. 5. The four agitators and the paddle wheel 12 are driven by means of a chain 24 runningover the respective sprockets, a drive sprocket S0 and an idler sprocket 51 in the manner shown in Fig. 5. The drive sprocket 50is carried on a drive shaft 52 which may be driven in known manner by an electric motor or from any suitable source of power. The agitators and the paddle wheel are turned to such positions that they do not clash in operation.

t The. shaker screen assembly 7 is, positioned on an incline with'its upper end being located underneath the hopper 11 and its lower end being provided with a shelf or apron 26 which projects into the opening 27 leading into the flue or air separator column 10. The screen shaker assemblycomprises an upper screen 28, a lower screen 30,

' and a bottom tray 31. These three members are mounted in a frame of suitable design with the shaker screen being supported on a plurality of rollers 32-32 extending across opposite sides ofthe machine as-shown in Fig. 3. The

lower end of the shaker screen assembly. is supported on shah-r rod 35 to ring 36 which fits over an eccentric 37 sup,- ported on a drive shaft 38 whereby the eccentric 37 may be driven at a suitable speed so as to impart a rapid oscillating or shaking action to the screen assembly. It will be understood that this particular method of vibrating or shaking the screen assembly 7 is illustrative of any of several types of vibrating or shaking mechanisms that may be used.

' The blower 8 comprises a blower housing 40 in which is located a blower wheel 41 mounted on a drive shaft 42 which is journaled at opposite ends between the sides of the frame 5. The drive shaft 42 is provided with a drive pulley 43 by which the blower may be driven by means of a belt (not shown) running from the pulley 43 to an electric motor or other driving mechanism (not shown). Various types of blowers of known commercial design may be used and selected on the basis of capacity for delivering the required volumn of air at the desired velocity for the flue or air separator column 10.

The opening 27 is wider than normal for a seed or grain cleaner. It must be suficiently wide to allow the cleaned wool to pass easily therethrough but not so wide as to cause the air column to leak out. In operation the air pressure on opposite sides of the opening 27 will either be balanced or there will be a slight negative pressure on the air column side so as to facilitate inward flow of the material. The upper edge of the opening 27 is defined by a curved sheet member 39 which may be adjusted by loosening the retaining bolts 4949 passing through vertical slots in the member 39. A width of 1 /2"2 /2 is suitable.

The flue or air separator column is S-shaped with a rectangular cross section which spreads out adjacent the bottom so as to connect with the discharge connection of the blower housing 40. The bottom end of the air column 10 is provided with a discharge spout 44, as indicated in Fig. 2.

The upper screen 28 of the shaker assembly 7 has openings 29 having a diameter of from 1" to 2" with about 16 to 64 of these openings per square foot of area of the screen. These openings are large enough so as to allow individual wads of mineral woolor rock wool and the smaller clumps of these wads to fall through the screen 28 onto the lower screen 30. Screen 30 may be either perforated metal or woven Wire screen having openings ranging from A to in diameter or size with about 16 to 144 openings per square inch. The openings in the upper and lower screens need not be circular in shape. For example, the openings in the lower screen 30 may be triangular in shape with the openings so arranged that they point toward the upper end of the screen.

The operation of the machine will now be described in connection with the diagram contained in Fig. 1:

Rock wool or mineral wool of commercial grade containing inclusions of hard foreign materials ranging from sandy fines up to large clinkers and pieces of slag, is fed into the hopper 6. The mineral wool or rock wool passes down through the hopper 6 and is distributed at even rate across the width of the machine and discharged onto the upper end of the shaker screen assembly 7. Referring to Fig. 1, the letter A designates a large composite clump or ball of the wool wads with hard particle inclusions, which is representative of the commercial product fed into the hopper 6. The paddle wheel 12 and the

agitators

15, 16, 17 and 18 reduce the size of the clumps somewhat but the action of these elements is neither intended to nor capable of effecting a complete separation of the composite clumps or balls A into the individual wool wads freed of hard particles. As the clumps A of the wads of mineral or rock wool and their hard foreign particle inclusions fall onto the upper screen 28 they are lightly bounced and shaken as they work down the incline until they are reduced in size sufiiciently to pass through the large openings 29 in this screen and fall onto so as to pass through the openings 29 before they reach the lower end of ,the screen 28. This \upper screen28 also serves totake out any unusually large foreign objects,' such as sticks, although such foreign matter is not ordinarily encountered in commercial mineral or rock;

wool.

The separatingaction of the. upper screen 28 is depicted in Fig. 1 bythe second group of wool wads and foreign particles indicated collectivelyatB. It will be seen that this 'collection is composed in part of smaller clumps'o f the wool wads such as are indicated at B1; individual wool wads free of foreign particles indicated at B2, large, hard particles B3, individual wool wads B4 which still have small pieces of hard material attached thereto, and fines indicated by the dots. This collection B is typical of the state of the product and material as it falls onto the second screen 30. As this collection B shakes or bounces down the inclined screen 30 the fines or sand falls through the small openings in the screen 30 and pass off through the discharge spout 45 at the bottom end' of the tray 31 in Fig. 2. The bouncing of the small clumps B1 on the screen 30 serves to break these up into individual wool wads while the bouncing of the individual wads B4 having hard particles attached serves to separate these hard particles so that by the time the material has reached the bottom end of the lower screen 30 it will be in the condition depicted collectively at C in Fig. 1. That is, it will be composed of individual wads of wool C1 together with separated pieces of hard particles C2 too coarse to pass through the fine openings in the screen 30.

The product in the condition indicated at C in Fig. 1 discharges from the lower end of the screen 30 through the opening 27 into the rising air column in the separator 10. The blower 8 is operated in such a manner that the volume and velocity of the upstream of air in the flue 10 will be adequate to carry off the lighter wads of cleaned mineral wool or rock wool which are now completely freed of hard foreign bodies, but will not be of suflicient strength so as to carry ofi any of the hard foreign materials which are separated from the mineral wool or rock wool and which will fall to the bottom of the separator and pass out through the outlet opening 44.

The eccentric 37 is rotated at such a speed as to impart a rapid vibrating or shaking action to the screen assembly '7. This vibrating or shaking action imparts a bouncing movement to the mineral wool or rock wool since this product has suflicient lightness and springiness that it lends itself to this type of movement or action. The hard, rela tively dense, foreign particles do not have this same tendency to bounce and this diiference in physical properties makes it possible to effect the separation of the foreign particles from the wool wads even though it is otherwise difficult or impractical to free the particles from the wool fibres.

It will be understood that certain modifications and changes may be made in the machine and the method of separation described above in connection with the ac companying drawings, without departing from the spirit and scope of the invention.

What is claimed as new is:

The method of cleaning mineral wool and rock wool wads to separate hard foreign bodies and sandy foreign particles therefrom including relatively large clumps containing all three of said materials, which comprises, spreading clumps of the unclean wool containing the other two materials onto the upper end of an inclined rapidly shaking upper screen having openings therein larger than the individual woolwads contained in said clumps and smaller than the larger of said clumps, breaking up said larger clumps into smaller clumps and wads and simultaneously shaking out said relatively large clumps by said rapidlyshaking operation of said upper ing through said upper screen on a rapidly shaking lower inclined screen having openings therein which ,are considerably ,finer than the'individual wool wads but large enough to pass the sandy foreign particles, breaking up the unbroken smaller vclumps into individual wads mgd separating .the hard particles attachedthereto and to the individual wads by said rapidly shaking operation of saidlower screen, and separating the individual wool wads from the hard foreign bodies by discharging the stream of individual wool wads andlarger hard foreign bodies from the bottom end of said lower screen into a rising air column having a velocity such that only the wool wads rise therein while the hard foreign bodies fall.

References Cited in the file' of this patent UNITED STATES PATENTS Re. 1,045 Booth Sept. 25, 1860 579,258 Constant Mar. 23, 1897 1,799,010 Farris Mar. 31,1931 1,905,152 L Clinton Apr. 25, 1933 2,217,538 Carson Oct. 8, 1940 2,280,903 ElliS0n"' Apr. 28, 1942 2,460,938 -Koehne Feb. 8, 1949