US2676059A - Method of and apparatus for treating material to be sprayed - Google Patents

Description

Ap 20, 1954 KEMPTHORNE 2,676,059

J. L. METHOD OF AND APPARATUS FOR TREATING MATERIAL TO BE SPRAYED Filed Feb. 8, 1951 .2 Sheets-Sheet 1 mmmIHIIlI/l I INVENTOR. rhme Lfizzz vifiozwe BY A TTORNEY April 20, 1954 J. L. KEMPTHORNE 2,676,059 METHOD OF AND APPARATUS FOR TREATING MATERIAL TO BE SPRAYED Filed Feb. 8, 1951 I 2 Sheets-Sheet 2 INVENTOR. rfames lfim ozriarae ATTORNEY Patented Apr. 20, 1954 UNITED STATES PATENT OFFICE METHOD OF AND APPARATUS FOR TREAT- INGr MATERIAL TO BE SPRAYED 2 Claims.

This invention relates to improvements in spraying apparatus and more particularly to a method of and unit for treating the material passed through such apparatus. The apparatus referred to are used for the spraying of asbestos fiber and other acoustical and thermal insulation materials. The materials to be sprayed, such as asbestos fibers and the like, are usually passed through the apparatus in the form of a stream of loose particles which stir up a considerable amount of dust. The dust problem has been so serious as to impair the health of workmen and create untidy conditions. Other trades frequently refuse to work in the same location at which insulation materials are being applied for the reasons mentioned. The fibrous materials, such as asbestos, are of amorphous cross-sectional outline, presenting a large and highly irregular surface outline which tends to have an abrasive effect on the blower and other parts of the apparatus through which the same passes.

Such materials have been projected from a gun head, with adhesive materials sprayed from the end of the head into the path of the fibers leaving the spray gun, but it has been found that the fibers tend to flower out upon leaving the spray gun head, as they are moved up to that point through the apparatus at greater than atmospheric pressure. Upon leaving the spray gun head and moving into the atmosphere, the materials, by virtue of reduced pressure, tend to flower out and have random movement, stirring up substantial amounts of dust. The application of adhesive to the material leaving the spray gun head by methods old in the art, is inaccurate and difiicult; the material leaving the gun head flowers out as above noted; furthermore, the adhesive penetrates the mass irregularly, leaving layers of dry fibers which fall off the surface to be coated.

The present invention is designed to overcome the objections above noted so that the material will pass through the apparatus without stirring up dust and without the usual abrasive action, the material further leaving the gun head and continuing onto the surface to be coated in a straight line. Pursuant to the invention, a treatl ng unit is provided having a discharge end for connection to the apparatus into the path of the material passing through the apparatus so as to apply a spray mist to said stream which will mingle and blend with the stream of particles to overcome the objections referred to and obtain advantages which will become apparent from the description below and by reference to the accompanying drawing.

Pursuant to the invention, the fiber stream is thoroughly and uniformly wetted in two stagesthe first or initial stage occurring on movement of the stream through the apparatus, the second or completion stage occurring in mid-air on projection of the stream from the apparatus.

The drawings show an apparatus embodying the invention comprising a hopper provided with means to meter the fiber through a discharge opening thereof, a suction blower connected to said hop-per discharge opening by means of a pipe having an inlet opening adjacent the hopper discharge opening, and a treating unit to wet the fibers opening into the pipe, so that on operation of the blower, the mist from the treating unit and the fiber stream treated thereby will be constantly drawn beyond said inlet and into the blower.

In the drawings:

Fig. l is a fragmentary elevational and schematic view of an insulation material spraying apparatus having applied thereto a treating unit of the invention,

Fig. 2 is an elevational view of said material treating unit positioned with the discharge end thereof disposed in a perpendicular plane to the path of movement of the fibrous material from the discharge opening of the hopper, the latter being indicated fragmentarily in said figure,

'Fig. 3 is a fragmentary perspective view of an apparatus embodying the invention,

Fig. 4 is an elevational view of said apparatus,

Fig. 5 is a similar view showing the invention applied to a tandem blower arrangement,

Fig. 6 Ba schematic view of another form. of the invention, and

Fig. 7 is a perspective view of another form of the invention.

As shown in the drawings, the invention applied to an apparatus H] for the movement, at greater than atmospheric pressure, of particles of fibrous material in a stream of random, loose form, from a hopper ll through blower l2 and through bore i3 of spray gun M and toward the surface S to be coated. The material moves in the path it defined by the various parts of the apparatus, including pipe 35 connecting the discharge opening 3 3 of hopper ll with inlet opening 33 ofblower [2, for example, in apparatus constructed in that form. The path 55 of mate rial through the apparatus continues through the discharge end ll of blower l2 and then out of the apparatus, as, for example, through hose 38 and out of bore E3 of spray gun head Hi and onto the surface S to be coated. The apparatus, in the form shown in the drawings and above referred to, exemplifies one of many different types of spraying apparatus to which the invention may be applied. The invention is applicable to apparatus for the spraying of a fibrous material from a hopper and through a spray gun in the path defined by the apparatus. The point of discharge of the fiber stream from the apparatus at 41 may be bore I3 of spray gun I4 or any other bore or opening through which the stream of fibers may be projected, and the reference, in this application, to bore I3 of spray gun I4 shall be deemed to include any other projection opening or means in the apparatus to the same or similar end. In the drawings, the path of the material through the apparatus is designated by reference character I5, the direction of movement of the particles in said path being indicated by the arrow I5 (Fig. 1).

The material treating unit of the invention comprises a mixing tube 2| having a discharge end 22 for connection to the apparatus so as to open into path I5 at a plane 23 (Fig. 2) at right angles to the axis of said path. Air and water lines 25, 25 are connected to opposite ends of mixing tube 2!, so that the water entering the tube will, at the discharge end thereof, enter and cross said path I5 in the form of a spray mist, mingling and blending with the stream of particles and accompanying said stream in its continued movement in path I5 and out of bore I 3 of the spray gun.

In Figs. 1 and 4, apparatus embodying the invention is shown, comprisin hopper i I provided with means, such as brush 33, to meter the fiber deposited into the hopper through discharge opening 34 thereof. Suction blower It is connected to hopper discharge openingtsi by means of pipe 35 having air inlet opening I8 adjacent hopper discharge openin 34. Treatin unit 2i opens into pipe 35 preferably at a point past inlet opening I8 thereof. On operation of blower I2, the mist discharged at 22 by treating unit 20 and the fibers treated thereby will be constantly drawn beyond inlet I 8 and into blower I2. When thus treated, it is found that the stream of .particles will continue its movement in the axial plane of the bore I3 of the spray gun and in the cross-sectional form of said bore in a straight line through the atmospheric pressure at the end of the spray gun bore and toward the surface S to be coated.

It has been found in practice that the treatment of the material, pursuant to the invention, results in the following advantages: Dust particles previously encountered in the movement of the particles through the apparatus are substantially eliminated. The spray mist from the discharge end 22 of mixing tube 25 thoroughly mingles and blends with the stream of particles so that said stream will continue in a straight projected line corresponding to that of the axial plane of bore I3 of the spray gun head, past the spray gun head and onto surface S. The stream of particles will be held together so as to form a more compact and better unified stream which will not flower out at the reduced pressure (atmospheric) encountered upon leavin the spray gun head.

The spraying apparatus Ill conventionally has motor driven means (BI, 40) for the hopper and blower, having a circuit for connection to a source of power, including the wire 30 conventionally controlled by a switch or the like. The motor 3I drives shaft 32 of brush 33 or the like 4 which projects the insulation material through discharge opening 34 of hopper II. This illustration is by way of example only of one of the various types of motor driven mechanisms known in the art for the projection of said material through the apparatus. It is desirable that the water flowing through mixing tube 2% and ,into the apparatus be cut off when motor 3! is shut off so that the treating unit will be operative only when necessary. To that end, an electrical power valve, such as solenoid 28, may be provided to control the path of supply of water to the mixing tube. Said solenoid may be independently switch controlled or may be connected, as by wire 29, in series to the circuit indicated by wire 38 for motor 3I. Thus, the

.power valve 28 will be opened to permit of the fiow of water into said mixing tube 2i only when the motor is on. A second solenoid 39 may be provided for a similar purpose-to control air inlet 2 3. Hand-operated valves 25, 2? may be incorporated in mixing tube 2! or otherwise associated with said treating unit so as to enable the operator to control the flow of water and air into the tube and their relative mixing ratios.

In Fig. 3, the treating unit 28 is shown secured to the apparatus intermediate the hopper and inlet port 36 of blower I2. By positioning the unit at this point, abrasion of the blower unit fan incident to the passage of dry particles of fibrous material and dust therethrough will be substantially reduced. The invention is shown in Fig. 3 in its simplest form, wherein a single treating unit 26 is suitably mounted in the apparatus to intercept the fibers moving in a path through the apparatus. The stream of fibers is projected from the apparatus at a velocity and pressure determined by such factors as distance from the apparatus to the surface to be coated, thickness of coating of fibers to be applied, and the like. The treating units may be used in tandern or other plural arrangement where necessitated by the job to be performed.

In Fig. 5, for example, a tandem arrangement of blowers is shown, the second blower 2a. increasing the pressure at which the stream of fibers will be projected from the apparatus. In such case, a second treating unit 26a may be secured to the apparatus to further wet the fiber stream.

Units may be secured to the apparatus to intercept the moving stream of fibers at a number of different points in path I5 through the apparatus, as shown in Fig. 6, wherein, in addition to unit 2!! which intercepts the stream of fibers between the hopper and blower, a second unit. 252) meets the stream after its passage throu h the blower.

The treating unit may be secured, as at 31 in Fig. '7, to the discharge end I"! of the blower unit,

if desired, instead of between the hopper and blower, or to any other point in the path I5 defined by the particles in passage through the apparatus.

The spray mist passes through the plane 23 defined by the discharge end of unit 28 preferably, as shown in the drawing, at right angles to path I5 of movement of the particles through the apparatus, so that said mist will efiectively intersect the movingparticles, thoroughly mingling and blending with the stream of particles, coating said particles and setting up a mist which will accompany said stream in its continued movement in said path and out of the bore of the spray gun head. The connection of the electric valves 28 and/or 39 to the source of power may be controlled by a single switch which also controls the current to the motors for the hopper il and/or blower I2. It is deemed desirable, although not essential, in carrying out the invention, that the flow of water and/or air into the unit 28 be controlled by the use of solenoid or similar electrically actuated mechanisms 28, 35, or the like for the purpose mentioned.

Pursuant to the invention disclosed in the application, the dust particles which accompany the fibrous material in passage through the apparatus are moistened and weighted so that they will be confined by the fiber stream moving therewith through and out of the apparatus. The dust particles will not follow courses dictated by their normal random movement when dry and will not tend to flower out on passing from the higher pressures of apparatus to atmospheric or room pressure. The present invention thus provides means for assuring the continued movement of the fiber stream out of the apparatus and toward the surface to be coated in a true projected path instead of in the objectionable flowering out or random movement.

In the conventional apparatus, the stream of fibers is discharged dry, accompanied by all of the dust generated in passage through the apparatus, so that the stream tends to flower out, discharge dust and stir up further dust in moving toward the surface S to be coated. Pursuant to the instant invention, the fiber stream 55 is projected from the apparatus as at 57 toward the surface to be coated, describing a path whose marginal edges it do not tend to flower out but tend to remain more constant, the stream of fibers being unaccompanied by random moving dust particles and stirring up no dust in moving toward surfaces S.

The stream of fibers 45 will have been wetted in an initial or first stage while moving through the restricted path 55 defined in the apparatus, pursuant to the invention. The stream of fibers will then be receptive to a second wetting or completion stage by action of nozzles Q8, Q9 (Fig. 4) mounted on spray gun Hi and connected to suitable air, adhesive and water lines 43, 44 to project jets of adhesives, water or other liquid as noted at it, as. Jets 48', 59' converge as at 50 onto stream 5 in mid-air, and in the path of movement thereof toward surface S to be coated. The nozzles 58, at may be mounted elsewhere in the apparatus so that the jets will intercept stream 45 in mid-air at or beyond point 41, but the arrangement above referred to, wherein the spray gun projects the stream of fibers 45 at a medial axial line from a point 137, and the jets 48, 69' are located for tangential contact with the stream 45 therebeyond, has been found to be admirably adapted to attain the objectives of the invention.

The term water, as used in this application, shall be deemed to include other liquids suitable to the same ends.

The air and water line connections to the treating unit 20 may be conveniently made at the ends of tube 2 l, but said tube may be of another structural form, with the air and water lines connected thereto at other points, if desired. For example, the tube 2! may :be of the flexible hose type or otherwise extended and the air-water inlet and control valves therefor may be at a point remote from the discharge end 22 of the tube, if desired, within the scope and purview of the invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An apparatus of the character described, comprising a blower having a center inlet and a peripheral outlet, a hopper having an outlet aperture, mechanism in the hopper for discharging fibrous particles through said outlet aperture, a pipe extending from th inlet of said blower to the outlet of said hopper said pipe being of substantially equal cross sectional outline to said hopper aperture and forming a closed connection between said aperture and the blower inlet except at its end communicating with the hopper said pipe at that point having a side opening constituting an air inlet through which air is drawn by the blower to mix with the fibrous material discharged from the hopper, a tube over said pipe having a depending branch intermediate its length communicating with said pipe through the upper portion thereof, and at a point spaced from the air inlet an air hose connected with one end of said tube, a water hose connected with the other end of said tube, valves in said apparatus for regulating the air-water flow into said tube, and a spraying hose extending from the outlet of said blower.

2. The structure recited in claim 1, wherein water tubes are mounted along the spraying hose, and nozzles carried by the outer ends of the water tubes spaced from each other circumferentially of the spraying hose and disposed at an incline for causing the water sprayed therefrom to intersect at a distance outwardly from the end of the spraying hose.

References (Jilted in the file of this patent UNITED STATES PATENTS Number Name Date 2,125,860 Sommer Aug. 2, 1938 2,178,539 Hill et a1. Nov. 7, 1939 2,363,480 Brownies Nov. 28, 1944 2,442,206 Kempthorne May 25, 1948 2,578,412 Fisher Dec. 11, 1951 2,585,004 Gillespie et a1 Feb. 12, 1952

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