US2209366A - Method and apparatus for feeding and distributing sludgy materials - Google Patents

Description

July 30, 1940'. 5 VANE I 2.209366 METHOD AND APPARATUS FOR FEEDING AND DISTRIBUTING SLUDGY MATERIALS Filed March 30, 1938 z zwwmw INVENTOR flI lg as/as J1 T6118 Patented July 30, 1940 UNlTED STATES METHOD AND APPARATUS FOR FEEDING AND DISTRIBUTING SLUDGY MATERIALS Augustus S. Vane, Irvington, N. Y., assignor to Bakelite Building Products 00., Inc., New York, N. Y., a corporation of Delaware Application March 30, 1938, Serial No. 198,887

11 Claims.

This invention relates to improvements in methods and apparatus for feeding and distributing sludgy materials, and is particularlydirected to improvements in the process and apparatus shown and described in a certain U. S. application of Thomas Brady, Serial No. 114,909, filed December 9, 1936.

In said prior application there is disclosed a hopper containing a sludgy composition. A discharge roll forms the bottom of the hopper and upon rotation removes a measured quantity of the composition from the hopper in the form of a layer upon its surface. Subsequently, the discharged layer of material comes under the influence of a high speed rotating distributor or impeller, for instance, a bristle brush which removes substantially all the composition' from the discharge roll surface and projects it where required.

-To improve the feed action and permit the feed of small quantities or thin films of the composition, the discharge roll surface is generally indented as by a threaded groove. In removing the deposit or film of composition from the discharge roll, contact between the roll surface and the brush bristles is made to an extent to remove the material in the grooves. The extent of contact is somewhat dependent upon the character of material being fed and the character of action believed to be suction occurring at the point of removal. 7

In operations upon a manufacturing basis, it has been found that an abrasive action occurs at the surface of the feed roll and also at the bristles of the brush distributor, resulting in wear upon these members. The action is substantial where the sludgy composition handled contains sharp abrasive particles, for instance, such as may be found in a hydraulic cement composition.

The wear upon the discharge roll is believed due to the substantially full removal of the composition from. its surface, whereupon relative motion occurs between the particles of composition and the roll surface at the area of contact, resulting in abrasion. The wear is increased by the beating and scraping action of the impeller fingers or bristles upon the roll surface where such occurs. A'lso, when the clear surface of the discharge roll re-enters the hopper, it comes in direct contact with the column of composition therein and before it emanates again with a new coating, a considerable abrasive action has taken place upon its surface.

Wear of the impeller fingers or bristles also occurs, some by abrading contact with the composition, but to the greatest extent by abrading contact with the roll surface. Moreover, where the roll surface is grooved, uneven wear of the impeller fingers or bristles, and similarly of the roll surface, also occurs.

Moreover, in said Brady apparatus the hopper side wall at the re-entrant side of the discharge roll has its lower end considerably below the crest of the discharge roll surface and slightly above a horizontal plane through the axis of the roll, 10 thus creating a gravity flow of the composition toward the re-entrant side of the hopper and-requiring a minimum clearance, if any at all, between the surface of the roll and the re-entrant hopper wall to prevent flow of the material out of the hopper at this point.- Accordingly, the discharge roll surface, when re-enterlng the hop-' per, must resist the pressure created by the directed flow of the composition at this point, and,

in effect, lifts the column of composition while 80 moving. This increases wear of the roll surface.

In addition, particles of the composition collect at the junction of the re-entrant wall and. roll surface by reason of the close relation of these parts, and are caught at this point. These also increase the wear.

Thus it will be seen that adjustments of parts and reconditioning of the discharge and impeller means must be regularly expected in the aforesaid operations, particularly where thin films of the composition are to be fed. It will be understood that the aforesaid difiiculties in operation may result in non-uniform feed and material distribution and such is reflected in the condition of the finished product and in its resultant. weight. These factors are exceedingly important, for instance, in the fabrication of cement coated roofing and siding materials. Even the use of the toughest and best of wear-resistant materials, including treatments thereof, has not entirely 40 overcome the resultant wear problem arising from the aforesaid particular operations, especially Where the fed composition is itself very abrasive. Furthermore, in the aforesaid character of operations, the use of a plain surfaced discharge roll is generally avoided because of th'e resultant considerable polish, a reduction in the composition withdrawing ability-and an-erratic I feed of the composition jwhere thin films are to be fed.

It is a general object of this invention to pro: videa process and means whereby the disadvantages of wear and operation aforesaidmay be substantially eliminated.

Another object of the invention is to provide 56 a method and means whereby sludgy compositions may be uniformly fed and distributed as coatings or surfacings or for any other purpose desired.

An additional object is to provide a method and means of uniformly feeding and impelling sludgy compositions comprising wetted material.

Another object is to provide a method and means to feed a moved and trowel mass of sludgy material in measured amounts at a uniform rate and evenly or uniformly spread the mass over a surface to be treated or to receive the same.

A particular object of the invention is to provide a method whereina predetermined layer of a composition is removed from a source of supply, and a portion of such layer is subsequently removed for transfer to a receiving surface and the remainder is returned to the supply for reforming into or to become a part of a layer substantially similar to the original layer subsequently emanating from the source of supply.

Another object of the invention is to provide a method of removing a predetermined uniform quantity of material from a moving feed means without causing substantial abrasion between the material and the surface of the feed means.

A further object is to provide a hopper and discharge roll combination, wherein the walls of the hopper are so positioned such that the composition to be fed only gravitates toward one side of the feed roll.

Another object is the provision of apparatus, simple in construction, easily assembled, in which the parts may be readily repaired or replaced, that will operate continuously in a uniform manner, that may be readily controlled and will efficiently carryout the functions for which it is intended.

These and other objects of the invention will, in part, be inferred, and in part be pointed out in subsequent description and inthe claims taken in conjunction with the accompanying drawing forming a part thereof. In the drawing, a preferred embodiment of the invention is illustrated in schematic form, it being understood that with the exception of indicated and/or described modifications, the construction details of the apparatus may be the same or similar to that described in the prior application referred to above. Moreover, it will be understood that the present process contemplates the use of any or all of the features and apparatus of the Brady invention aforesaid, although they may not be otherwise specifically referred to herein.

Furthermore, inasmuch as the methods and apparatus are particularly applicable to the cement surfacing of roofing and siding materials, the description has been particularly directed to the application of my process for this embodiment, but it will be understood that my process is applicable to other applications and numerous materials not specifically mentioned herein, and any modifications essential to such applications, as may be within the spirit of my'invention, are therefore contemplated.

In the drawing, there is shown in elevation a schematic arrangement of the parts of a single unit of my feed and distributing apparatus, the arrows indicating preferred directions of operation or directions of adjustment of the several parts thereof.

Broadly speaking, I have discovered that the problems of operation referred to above, may be largely overcome and the necessity of forming thin films of sludgy composition where it i5 16- sired to feed small amounts thereof, may also be entirely eliminated, by a process initially building upon a feed means and directing from a source of supply of the composition to be fed, a properly calibrated layer of the composition, of substantial thickness, subsequently removing a surface portion of the formed layer for distribution, the amount being wholly dependent upon the quantity of material to be distributed and finally returning the remainder of the formed layer to the source of supply, and repeating this cycle of operation.

I have found that with a discharge means having a suitable traction surface, an initial layer of substantial thickness and desired formation may be formed of the composition to be fed. When such a layer is fed to the distributor or impeller and only a portion is removed, there is no abrasive action between the fed composition and the surface of the feed or discharge means, and the abrasion previously obtained between the distributor and discharge means surface is also eliminated, for in the instant process there is substantially no relative motion between the fed composition and the feed or discharge means surface, and likewise no contact between the distributor and feed or discharge means surface.

Moreover, when the remainder of the original layer is returned to the source of supply, it is believed that only a further part thereof intermixes with the composition in the source of supply, and that a portion of irregular character remains upon the surface of the feed element as a nucleus upon which to build a new layer as the feed element moves through the source of supply; the nucleus, with its addition, being calibrated as it leaves the source of supply into a layer of substantially original size and shape. In this manner, the substantial wear occurring at this point of operation in the operations previously referred to, is also substantially eliminated. I have further discovered that the proper positioning of the composition supply with respect to the feed element also reduces the possibility of abrasion between the composition and feed element surface.

Referring now to the drawing showing a schematic arrangement of the feed and distributing unit, the details of the parts of which are substantially similar to those disclosed in said prior application Serial No. 114,909, the numeral l0 represents a driven feed or discharge element, for instance, a rotatable steel roll for continuously removing a quantity of sludge composition from a source of supply I2, for instance, a hopper containing the sludgy composition It. The feed roll surface preferably possesses sufficient traction to permit satisfactory adherence of the sludgy composition when the roll surface passes through the hopper to form the initial layer. The surface of the feed element may be plain, as substantially no abrasion by movement of the composition relative thereto is to be expected. Obviously, the roll may have a grooved, threaded, or any other modified surface, if desired.

- The hopper l2 preferably has an open bottom and is positioned in the indicated manner above the discharge roll III, which, together with an adjustable gate roll and troweling roll l6, provide its bottom enclosure. The gate roll is positioned at the discharge side of the hopper and preferably has a resilient surface, for instance, one of rubber. The size, direction of rotation and surface speed of the gateroll l6 respectively, relative to that of the feed roll, should be such as to produce a wiping and/or smoothing action, herein referred to as troweling, upon the sludgy composition against the feed or discharge roll surface and to continuously level and reduce the thickness of the layer formed until a minimum is reached at the nip of the rolls. This working upon the sludgy composition by the gate roll assures a constant and uniform delivery of material, irrespective of the thickness of the layer being fed. It also assures good adherence of the sludgy composition to the feed roll surface during the operations so that when the fed material is contacted by the distributor, whole sections of the fed layer will not be torn away from the discharge roll surface. In certain operations with a wet cement composition, it has been found satisfactory to operate the discharge and gate rolls at respective R. P. M. speeds in the proportion of about 10 to 2.75, with the discharge roll operating at about 6 or more surface feet per minute, depending upon the rate at which dis-,

charge of the fed composition is to occur. Satisfactory sizes of discharge and gate rolls have been found to be in the order of about 14 and 8" respectively. The gate roll is, moreover, ad-

justable to and away from the feed roll surface to calibrate a composition layer of desired shape and thickness. It is preferred that two adjustments as indicated by the inner arrows on the member l6, be provided, thus making possible a wide range of adjustment, both fine and coarse. In one operation, using a hydraulic cement composition including a sand or marble aggregate and having a slump of between 6 to 7%", according to the A. S. T. M. cement -slump test, I have built upon the roll as much as a layer of such composition.

The measured layer of sludgy composition upon discharging at the nip of the calibrating and feed members is carried by the discharge roll 10 into the operating range and action of the distributing or impelling device l8 extending substantially parallel to the feed or discharge roll III. In the exemplified form, the distributor may be a rotary impeller, for instance, a wire bristle brush or the like, having a considerable surface speed, so that its bristles may impart a throwing or impelling action to any material which is released from "75 largely dependent upon the type of sludgy coatthem by reason of centrifugal force caused by the brush rotation and any fiexure set up in the bristles themselves. The bristles should be of such size and length as to provide soft fiexure without permanent deformation. A' surface speed of about 4,000 feet per minute has, in many instances, been used with satisfactory results.

The distributor I8 is located adjacent the feed roll and above the surface or material 20 to be treated with or to receive the composition. Preferably, the position is one permitting the greatest impelling efficiency obtainable without contacting the surface 20 and to avoid, an excessive throwing of the sludgy composition in a direction parallel or away from the said surface. The surface 20 preferably moves or is carried by a conveyor 22 past the discharging stream of particles 24 of sludgy material. It will be noted from the drawing that the greatest portion of the sludgy composition is impelled substantially normal to the moving surface 20, and the remainder at a more inclined angle to assure full coating of surface irregularities. such as exist on a granule surfaced roofing web. In certain operations, the

surface 20 has been moved at speeds of between 50 to- 200 feet per minute with satisfactory results. The various speeds will, of course, be

the layer) carried by the feed roll.

ing composition and the thickness of coating to be applied in a single application. The proper requirements will be readily ascertained in actual operation.

The rotary distributor should be adjustable as indicated by the inner arrow on the member 18 with relation to the surface of the discharge roll l so as to remove the proper amount of composition from the layer 26 (but not them- It is preferred that a very accurate screw adjustment be provided so that the distributor may be readily adjusted with a high degree of accuracy and within as close limits as the conditions of operation may require. I

It will be recognized that during the distributing operation thereis no relative movement between the layer 26 of composition material on the discharge roll and the surface of the discharge rollitself, and that any abrasion occurring will be between the bristles of the distributor and the particles of fed composition. However, by reason of my novel process this abrasion is not of the very objectionable character previously obtained, and is substantially uniform. It requires seldom adjustment of the impeller.

The unused portion 28 of the composition layer remains upon and is carried by the discharge roll l0 afterit leaves the action of the distributor 18,,

andre-enters the supply means or hopper It] at the rear or re-entrant side wall 30, which is opposite to that from which it originally emanated. This wall or part thereof forms the gate 32, which is adjustable with relation to the discharge roll surface to accommodate the thickness layer returning to the supply means.

A feature of the invention resides in the positiming of the hopper or supply means walls. Thus the terminus of the opposed hopper side walls occurs immediately above the gate and discharge rolls respectively, and at one side of the vertical center line 34 of the discharge roll, 1. e., at one side of a plane through the longitudinal axis of the discharge roll and plumb with respect to said axis. Reference to the drawing will clearly show this relation and it will be seen that the rear side wall 3lI-32 is on the same side of the vertical center line 34 as the forward or discharge side wall 36 and its lower terminus occurs just beyond the high point or crown 38 of the discharge roll. In this manner, the amount of roll surface area contacted by the composition in the hopper is practically reduced to part of what itwas in the prior application aforesaid, and more particularly the terminus of the rear wall 30-32 is such as to prevent any escape by gravity flow of the sludgy composition l4, and to prevent the substantial amount of abrasive action which occurred in the previous deviceby reason of particles catching atthe rear gate.

It will be understoodthat the various .elements of my apparatus may be constructed, supported, operated, driven and adjusted in the manner and by the means described for similar elements in the aforesaid application Serial No.

114,909. Furthermore, while the instant drawing will be in reverse direction if the unit facesin the opposite direction. Moreover, the directions of rotation of the various elements may be varied ir. the manner and according to the combinations referred to in sa-idprior applicationSerial' No. 114,909. It will also be appreciated that my novel process and apparatus may be used in multiple tandem arrangements with or without the auxiliary equipment also shown and described in the aforesaid prior application.

The present process has particular application to the coating of a granular surfaced asphalt impregnated and coated roofing Web in the making of cement coated roofing and siding elements. In such case, the sludgy composition will be, for example, one including hydraulic cement, a suitable aggregate, for instance, sand or marble, and sufficient water to give the mixture proper plasticity. Satisfactory operations have been conducted with a mixture having a slump of approximately between 6% to 7 according to the A. S. T. M. cement slump test. It will be understood that other types of materials such as sugar frostings, etc., may be employed in my process without difliculty.

In carrying out the process, a batch of the sludgy composition is fed to the supply means or hopper l2, as by the means 40, whereupon it continuously passes out of the hopper between the nip of a continuously rotating discharge and gate rolls ID and 16 respectively, as a layer 26, and is continuously conducted away upon the surface of the discharge roll. The layer of composition material is then continuously conducted away upon the discharge roll surface to the impelling device or distributor l8, which continuously removes a surface portion of the moving layer and spreads it over the continuously moving surface 20, the discharged material being conducted thereto in the form of a stream 24 of dispersed particles. Thereafter, the discharge roll l0 continues its motion and returns the remaining portion 28 of the feed layer to the hopper, where more or less of it intermingles with the further supply M of material therein and the remainder is continuously rebuilt into a'layer of the original shape and size. 7

In starting operations, it is preferred that the layer which is to be fed by the feed roll be built up in several rotations of the feed roll. In this manner, the base portion of the layer which may remain during the continuous operation of the apparatus, will have been firmly troweled by the gate roll. It will be understood, however, that the full thickness may be obtained in the initial operation, if desired.

It will be understood that the coating unit may be moved relative to the surface to be treated, when desired, and the said surface 20 may be stationary. Moreover, the operations may be intermittent at any stage.

From the above description of my novel process and apparatus, it will be seen that I have provided a new and novel method of and apparatus for improving the feed and distribution of material, particularly a sludgy composition, to a receiving surface, and that the process and apparatus eliminates the necessity for forming thin films of the composition, eliminates the necessity for using special feed rolls, eliminates abrasive action upon the feed roll surface and substantially reduces the abrasive action upon. the impeller to a minimum. Moreover, the method and apparatus provides a practical coating application without requiring constant replacement or adjustment of parts at considerable expense. It will be understood that various modifications may be made in the exemplified apparatus and process without departing from the spirit of my invention, which I desire to be construed as broadly as the appended claims, taken in conjunction with the prior art, may allow. The details of construction have been given for illustration, not restriction. Moreover, various details in the foregoing description have been referred to by specific terms for convenience. These terms are to be given as broad an interpretation as the state of the art will permit.

I claim:

1. The method of applying a sludgy composition to a receiving surface comprising providing a source of the composition, forming a continuous layer of the composition of predetermined section from said source, continuously moving said layer past a distributing position, continuously removing a surface portion of the formed layer during its movement past said distributing position, distributing said removed portion in a particle stream over the receiving surface, continuously moving the remainder of said formed layer into association with additional of said composition at the source, and continuously reforming a layer thereof of substantially original size and shape.

2. The method of applying a sludgy composition to a receiving surface comprising discharging a layer of the composition from a source of supply, moving said layer into contact with a distributor, removing a portion of said formed layer, distributing said removed portion over the receiving surface, returning the remainder of said formed layer to the source of supply and redischarging the same as a layer of substantially similar size and shape to the originally discharged layer.

3. The method of applying a sludgy composition to a receiving surface comprising moving said receiving surface, continuously discharging a layer of the composition of substantially uniform section from a source of supply containing said composition, continuously moving said formed layer into contact with an impeller distributor, continuously removing a surface portion of said formed layer, continuously impelling and distributing said removed portion in particle form over said moving receiving surface, and continuously returning the remainder of said formed layer to the source of supply.

4. Apparatus for distributing a sludgy composition comprising a hopper to receive a supply of said composition, rotary feed means to remove quantities of the composition from said hopper, gate means adjacent said feed means to calibrate the amount of composition removed by said feed means and to form a layer thereof on said feed means, and throwing means comprising a plurality of projecting elements to remove the composition from said feed means, said throwing means positioned out of contact with said feed means but in a position whereby to contact and remove only a portion of the layer carried by said feed means leaving intact a layer of diminished thickness.

5. Apparatus for applying a sludgy composition to a' receiving surface comprising a hopper for storing a supply of the composition, a rotary feed roll for withdrawing composition from the hopper, a gate roll in association with the feed roll to calibrate and form a layer of the composition upon the feed roll and a rotary bristle impeller out of contact with said feed roll but positioned to remove a portion of the layer of composition carried by said feed roll and leave a layer of diminished thickness on the roll for return to the hopper.

6. Apparatus for applying a sludgy composition to a receiving surface comprising a hopper to store a supply of the composition, a rotary feed roll forming the bottom oftsaid hopper, layer forming means in conjunction with the feed roll to cause said roll to withdraw thereon a continuous layer of the composition of uniform section, a rotary impeller out of contact with said feed roll but positioned to remove a surface portion of said layer carried by the feed roll and throw the same as a stream of dispersed particles upon a receiving surface immediately below said impeller and feed roll.

7. Apparatus for applying a sludgy composition to a receiving surface comprising a rotary fe'ed roll to feed a continuous layer of composition, a hopper positioned over the feed roll surface, said hopper having opposite sides extending longitudinally of the roll, said sides positioned to enclose a portion of the roll surface at one side of a plane through the longitudinal axis of said roll and plumb with respect to said axis and means out of contact with said feed roll but positioned to remove a portion of said layer carried by the feed roll and throw the same in a particle stream against the receiving surface; said longitudinal sides each having adjustable gate means at their lower extremities whereby to measure the fed layer-of composition and to accommodate the return of the undistributed portion thereof to the hopper.

8. Apparatus for applying a sludgy composition to a receiving surface comprising, a rotary feed roll, a hopper over the feed roll and containing a supply of composition, said hopper positioned to gravitate said composition to a portion of the feed roll surface inclined in one direction, rotary gate means at the discharge side of said hopper positioned as to form a layer of said composition upon said feed roll when rotated, a rotary impeller out of contact with said feed roll but positioned to remove a portion of said layer of composition carri'ed by said feed roll when rotated and an opening between said hopper and feed roll to permit return of the remainder of said layer of composition to the hopper.

9. The method of applying coating composition to a receiving surface comprising providing a source of the composition, moving a layer of the composition from said source, removing a predetermined surface portion of said layer in a plurality of small segments and while said turning the remaining material of said formed layer to said source and forming a new layer of the composition for further distribution.

11. The method of applying coating composition to a receiving surface comprising providing a source of the composition, forming a layer of the composition from said source, removing a surface portion of said layer and leaving a layer of diminished thickness, impelling the material of said removed portion against the receiving surface, moving the material of the diminished layer into association with additional of said composition at the source and continuing the formation of a layer similar in size to the original layer.

AUGUSTUS s. VANE.

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