IL23013A - Method of and apparatus for manufacturing heat insulating material - Google Patents

Description

Method of for heat insulating 22060 2 This invention relates to the manufacture of a heat insulating material from coarsely comminuted cellulosic matter intimatel mixed with a flreproofing subatance which consists of or includes boric acid or cellulosic matter may be of any suitable cellulose pulp or the Waste newsprint has been found to bo a particularly inexpensive and suitable raw and the invention will be cribed herein with reference to the wider ity of the invention being In addition to being the newsprint provides an excellent skeleton for the material since fibers are cellular and therefore contain a large number of dead air since the newsprint will be used after appropriate including the removal of the it does not repel the boric acid which provides the material with its main fireproofing In the boric acid will be specified as the fireproofing A heat insulating material of this comprising about by weight of newsprint of boric has been described in patent specification It has also been proposed to manufacture a material of this type in which the fireproofing substance includes a lesser proportion of boric about by together with ered aluminium This latter material has not the same perfect fireproofing properties as has the but its manufacture is equally contemplated by the present 3 Boric acid of much more expensive than it is important that no boric acid is that larger proportion thereof be admixed to the newsprint than is required in each thero exists a real need for close quantity control in the feed of the newsprint and boric acid in the course of the manufacture of by its very this material makes it very difficult to maintain close quantity control over two This is particularly true continuous operation which has to be resorted to in mass The problems Inherent the continuous feed of measured quantities of any type of pulverized material are multiplied in the case of a material such as On the other the course of such tinuous the powdered fireprooflng substance is fed directly into the mill in which the bulk newsprint is the former admixed to the latter in too loose and uniform a manner and does not firmly adhere to As a some of the boric acid may actually be shaken off the fibers of the It an object of this Invention to eliminate these drawbacks and to provide a continuous method of and apparatus for manufacturing a material of the kind indicated above in such a way that the newsprint becomes firmly charged with the desired percentage of boric The Invention consists in a method of continuously manufacturing materials from comminuted celluloslc matter and powdered fireprooflng substance 4 wherein the fireprooflng substance is continually duced into a stream of coarsely comminuted cellulosic matter a predetermined ratio of the two and the mixture thus produced is subjected to a comminuting and beating operation calculated to beat the fireprooflng substance into the fibers of the cellulosic invention also provides an apparatus carrying out the includes a first mill for comminuting cellulosic means for delivering the comminuted cellulosic matter controlled rate of feed to a chute through whioh it descends in a free a second mill disposed to receive the cellulosic matter from the and means for delivering the fireprooflng substance at a controlled rate of feed into the said The mills are preferably hammer The means for delivering the cellulosic matter and the fireprooflng substanoe to the chute are preferably constituted by separate the conveyor for the cellulosic matter is disposed in a substantially horizontal position and the matter is fedfrom above to In this case it is preferred to provide at the intake end of the veyor a hopper in which the cellulosic matter collects up to a level clearly above the apexes of the helical turns of the The conveyor for the fireprooflng substanoe is preferably disposed in the ascending 5 By a further preferred feature of the the outlets of the mills are connected to blowers whioh aspirate the ground and deliver it into screens are provided in conjunction with the mills for retaining such particles the cellulosic matter as exceed the intended size A preferred embodiment of the apparatus according to this invention is illustrated and by way of example in the accompanying This apparatus includes a first mill 10 disposed in a housing 11 having an inlet 12 and an outlet mill comprises a number of hammers 14 plvotally mounted in the part of a drum The drum rotates wise about an axle as indicated by the A screen 17 extends across the housing between the hammers 14 and the outlet the meshes of the screen have preferably a width of about 19 to Newsprint is in bulk through the inlet 12 of the mill 10 and pulverized as it is struck by the and forced through the screen Although the newsprint may be obtained virtually any it should preferably be clean printers ink so that it has a uniform whitish Since the rate of feed is regulated at a later stage of the the newsprint may be fed into the mill 10 more or less at Of other types of pulverizing equipment may be used though a hammer mill has been found to be especially well suited for this 6 The comminuted newsprint is aspirated through the screen means of a conventional centrifugal blower 18 whose central part is connected to the outlet while its tangential outlet is oonnected by a rising conduit 19 to the upper portion of a air separator This consists of a housing 21 where top opening 22 is but not by a cap The conduit 19 makes a tangential connection with the separator housing 21 so that the pulverized newsprint enters the separator housing along the circumference It is thereby imparted a whirling motion as it fall3 through the whereby the air is separated from the solid mass and can escape through the opening The solids emerging from the separator collect and thereby become more or less compacted into a in a downwardly flaring hopper 24 which is connected at its top to the lower end of the separator housing and at its lower end inlet end of a conveyor This feeds the newsprint to the upper end of a substantially vertical chute The proceeds at such a rate that in the hopper 24 there remains a store of newsprint mass up to the level 27 above the upper end of the conveyor Owing to this arrangement the conveyor remains fully covered with and embedded in the mass of As the conveyor is rotated by means of a pulley any excess of comminuted newsprint is removed from above the conveyor by one or more weirs 29 just before the mass proceeds into the tubular housing 31 which narrowly surrounds the the conveyor running at the desired 7 the pulverized newsprint is fed into the chute at a uniform and controlled The bottom end of the chute 26 opens into the inlet may 32 of the housing 33 of a second mill 34 the same design as the mill with hammers 36 mounted in a rotating a screen 37 extending across the and ah outlet The fireproofing commercially available boric acid of purity with a partiole size of mesh standard is supplied to a container 38 having a lid 39 at one end and an outlet 40 at its other where the rate of feed the substance is regulated at a later stage the substance may be introduced into the container A mixing mechanism rotatable by means of a pulley is mounted within the container for the purpose of breaking up any lumps of the substance and homogenizing its particle Por the same purpose the substanee may be subjected to vibration by means of a vibrator 43 or the like attached to the outlet end of the Prom the container the substance is fed by means of a conveyor 45 upwards through an ascending conduit 45 whose upper end opens downwardly in order to discharge the substance into a tray The open end 47 of the trey extends through an opening into the chute A vibrator 48 is attached to this tray and so adjusted that it delivers a uniform feed of the desired quantity of the powdered substance into the stream of failing verized newsprint freely through the The 8 substance mingles with the newsprint and the mixture enters through the inlet into The hammers of the have the main task of beating the powdered substance into the fibers of the the fibers are further At this stage the fibers and fireproofing substances are no longer but it will be more appropriate to speak of fibers charged with the fireproofing or for The charged fibers are then aspirated through the screen 37 and outlet 35 by a blower 49 which may have the same design as the blower This delivers the charged fibers through a rising conduit whose upper end is connected at 51 to the upper portion of the housing 52 of a second separator Similarly to the separator the separator 53 has a top opening 54 covered but not closed by a cap the charged fibers are awirled along inner wall surface of the separator housing 52 and fall down while the air separates from the fibers and through the outlet The lower end of the separator housing 52 is connected to the upper end of a hopper 56 which serves for collecting and compacting the mass of charged The opening in the lower end of the housing 52 is somewhat larger than the opening through the separator housing 21 since through it there passes a larger bulk of the charged An agitator ouch as blades 57 radially fixed to a rotating may be disposed in the part of the hopper 56 in order to prevent material from bridging in the 9 lower end of the hopper 56 is connected to the upper end of the housing of a conveyor for feeding the charged fibers into the upper end of a chute The speed of this second conveyor 58 is adjusted to maintain the desired rate of feed of the charged fibers into the chute 59 and to prevent accumulation of fibers in the hopper 56 above the From the chute the charged fibers flow into a spout This delivers them into bags 61 carried on supports which are thus filled one after the and replaced as they are insufficientOCRQuality

Claims (10)

1. , A method of continuously manufacturing heat-insulating materials from comminuted cellulosic matter and a'owdered fire proofing substance consisting of or including boric acid or borax, wherein the flreproofing substance is continually introduced into a free-falling stream of coarsely comminuted cellulosic matter at a predetermined ratio of the two ingredients, and the mixture thus produced is subdected to a comminuting and beating operation calculated to beat the fireproofing substance into the fibers of the cellulosic matter.

2. A method according to Claim 1, wherein the cellulosic matter is wood pulp, paper, cellulose wadding or the like.

3. , A method according to Claim 2, wherein newsprint is used as the cellulosic matter.

4. A apparatus for carrying out the method according to any of Claims 1 to 3, comprising a first mill for comminuting the cellulosic matter; raeane for delivering the comminuted cellulosic matter at a controlled rate of feed to a ehuto through which it descends in a free fall? a second mill disposed to receive the cellulosic matter from the chute; and means for delivering the flreproofing substance at a controlled rate of feed into the said chute.

5. · An apparatus according to Claim 4, wherein the conveyor for the cellulosic matter is disposed in a substantially horizontal position and the matter is fed from above to the Conveyor,

6. An apparatus according to Claim 5» comprising at the intake end of the conveyor a hopper in which the cellulosic - 11 - 23013/2 matter collects up to a level clearly above the apexes of the helical turns of the conveyor.

7. An apparatus according to Claim 4» 5 or 6, wherein the outlets of the mills are connected to blowers which aspirate the ground mass and deliver It into cyclone-type separators.

8. An apparatus according to any of Claims 4 to 7, wherein screens are provided in conjunction with the mills for retaining such particles of the cellulosic matter as exceed the intended size thereof.

9. An apparatus according to any of Claims 4 to 8, wherein the means for feeding the flreproofing substance to the chute includes a container for the flreproofing substance, means for agitating the substance to keep it in powdered form, a conveyor for delivering the substance to a tray extending into the chute, and means for vibrating the tray.

10. An apparatus for carrying out the method according to any of Claims 1 to 3, substantially as described herein with reference to the drawing. For the Applicants RC/rb