US2361601A - Aspirating separator - Google Patents

Description

Oct. 31, 1944. R. J. 5. CARTER ASPIRATING SEPARATOR Filed April 11, 1942 5 Sheets-Sheet 1 Oct. 31, 1944.

R. J. s. CARTER 2,361,601

ASPIRATING SEPARATOR Filed April 11 1942 5 Sheets-Sheet 2 0a. 31, 1944. R CARTER 2,361,601

ASPIRATING SEPARATOR Fi1ed April 11, 1942 5 Sheets-Sheet 5 jazz/02 .Eafiarf Jm ear/W 1944- R. J. s. CARTER ASPIRATING SEPARATOR 5 Sheets-Sheet 4 Filed April 11, 1942 Oct. 31, 1944. J 5, CARTER 2,361,601

ASPIRATING SEPARATOR Filed April 11, 1942 5 Sheets-Sheet 5 Patented Oct. 31, 1944 UNITED STATES PATENT OFFICE ASPIRATIN G SEPARATOR Robert J. S. Carter, Minneapolis, Minn.

Application April 11, 1942, Serial No. 438,634

4 Claims.

- also involves an improved method or process of In machines of the type just indicated, it has hitherto been the common practice to cause the stock to float on or over the screen by means of an air blast that produces an upward pressure of air against the bottom of the screen or perforated deck and through the perforations of the screen or deck. In the hitherto used screen just noted, it is found that the upwardly directed air blast will produce, below the screen, a pressure very greatly in excess of atmospheric pressure and will produce, above the screen, an air pressure that is less than the air pressure below the screen, but, nevertheless, to a considerable extent above atmospheric pressure. This statement is especially true when a protecting hood is placed above the screen.

In accordance with my invention a marked improvement in the desired separating action is accomplished by placing a hood over the screen and producing within the hood a partial vacuum or pressure that is very greatly less than that of the atmospheric pressure. Moreover, with the fan or other device arranged with its air intake to produce the upward fiow through the perforations of the screen, located above and operating solely from above the screen, a partial vacuum much less than that produced above the screen, but less than atmospheric pressure, takes place below the screen.

As a further and highly important novel feature involved in my improved apparatus, the screen or deck is provided, near or at its delivery end, with a blank or imperforate zone or portion; and the intake of the fan, which is to produce the partial vacuum above the screen, is located over or above this blank or imperforate portion. Very important actions result from this novel arrangement just indicated, and which will be more fully discussed and disclosed after having first described more in detail a preferred embodiment of the invention which also includes various other minor but important features. v

The accompanying drawings, wherein like characters indicate like parts throughout the several views, illustrate what I believe at present to be the preferred embodiment of the invention.

Referring to the drawings:

Fig. 1 is a view in elevation looking at the right hand side of the machine, some parts being broken away and some parts being shown in vertical section;

Fig. 2 is a horizontal section taken approximately on the line 2-2 of Fig. 1;

Fig. 3 is a View in elevation looking at the rear end of the machine, some parts being broken away and shown in section;

Fig. 4 is a view in elevation looking at the left hand side of the machine, some parts being broken away and shown in section;

Fig.5 is a View in vertical section taken approximately on the line 55 of Fig. 1, some parts being shown in full;

Fig. 6 is a fragmentary viewin elevation looking at parts found in the vicinity of the line marked 66 on Fig. 5, some parts being broken away; and

Fig. '7 is a fragmentary view taken in section on the line of Fig. 5.

All of the parts of the machine are mounted directlyor indirectly upon a strong rectangular framework indicated as an entirety by the numeral II]. This framework is preferably made of channel steel properly trussed and braced. The element herein frequently designated as a screen does not accomplish separation of the particles of mill stock or stream, does not operate as a customary screen through which the finer particles are passed, but operates as a perforate feed deck through which air is drawn by partial vacuum or suction produced above the screen, and the arrangement is such that the commingled stock will be moved with a'sort of a floating action over the screen surface. In fact, a portion of this perforate feed deck is blank or imperforate for a purpose already indicated in ageneral way but hereinafter to be more fully described. The perforate surface is preferably a finely woven wire screen II which is directly secured to and tightly stretched over a rectangular screen or deck frame l2. The feed deck is made up of this screen ll and an imperforate deck portion l3. The screen of deck frame 12 is mounted on a rectangular shoe or carrying frame [4 shown and preferably made of angle iron to which is welded a flange-forming bar l5, see particularly Fig. 5. The screen, and in fact the complete deck lll3, is inclined transversely and at its lower side is fulcrumed to the shoe [4 at 16 and at its opposite side is adjustably secured to the shoe by suitable means such as right and left center wheel screws IT.

The shoe M is supported for vibratory movements by four upright links l8 which, at their upper ends, are pivotally connected to the sides of the shoe by pivot pins l5. At their lower ends the links I8 are pivoted on bushings 2E3 applied on the threaded ends of a transverse spacing tube 2! located between clamping nuts 22, best shown at the left in Fig. 5. Extended through the spacing tube 2| is a tie rod 23, the ends of which extend through segmental slots 24 formed in.the H webs of a pair of parallel transversely spaced carrying beams 25". These slots 24 are'concentric to the-axis of the pivot pins l9, see particularly Fig. 1. The extended ends of clamping rod 23 are threaded and provided with nut-acting clamping wheels 26 which, when tightened, clamp the ends of spacing tube 2! against the inner faces of the webs of the two beams 25. The two beams 25 are pivoted on a transverse rod of shaft 21, see Fig. l, and which, as shown, is provided with nut-acting wheels 23' at itsouter ends. Extended through the long free or rear ends of the two beams 25 is a clamping rod 29provided on its threaded outer ends with nut-acting hand wheels 30 or'the like. Clamping rod 29' works free from all of the fixed parts of the frame-work and when its nut-acting wheels 38 are tightened, tightly clamps the ends of the beams against the sides of the framework. The beams 25 and parts carried thereby, including the shoe and screen, are connected for common adjustments by suitable means preferably involving manually operated transverse shafts 3| connected by miter gears. 32 to short upright screw rods 33 that work in nut-acting sleeves 3d shownv as provided with projecting arms 35 that bear against or are rigidly secured to the vertically movable free end portions of the two. carrying beams 25, seeparticularly Fig. 3. Shaft 3|, at one end, is shown as provided with an operating crank or handle 36.

Mounted on the ends of the spacing tubes 2! and extending parallel to the curved slots 24, see

particularly Figs. 1, 4 and 7, are gear segments 31..

The front pair and the rearpair of these segments 31 are arranged to beindependently operated by co-operating pinions 38 on transverse shafts 39 that are journaled .in the beams 25 and provided with operating cranks or handles it). The perforate feed deck is arranged to be reciprocated through a pitman or connecting rod 4|, see particularly Fig. 1, and is driven from a crank- shaft 4,2 mounted in bearings 53 on the front ends of the pivotally supported beams 25. Crank-shaft Gamay be driven in any suitable way but, as will presently appear, is provided, with a pulley 54 over which runs a power-driven belt 45. The extended end of pitman 4| is pivotally connected at 36 to the shoe M. In the preferred and illustrated arrangement the pitman 4i and connections described are in duplicate with the connecting rods one at each side of the shoe, see particularly Fig. 2.

The farinaceous stock will, of course, be delivered ontothe perforated orscreen portion of the feed deck; and preferably, this is accomplished through a delivery spout l! in which is a wing feeder or feed gate 58, see particularly Fig. l. The shaft 49 of wing feeder 48 is journaled in suitable bearings on the framework and at one end is provided with a pulley 50.

Secured on the face on the feed deck is a banking rail 52, see Figs. 1, 2 and 4, that marks a dividing line between the perforate portion H and imperforate portion 13. By reference particularly to Fig. 3, it will be seen that, in'the preferred embodiment of the invention illustrated, the banking rail 52 extends in a general direction obliquely or diagonally across the deck, starting at the upper receiving end portion of the deck and terminating at the lower delivery end portion of the deck. The fan that creates partial vacuum or pressure below atmospheric pressure above the feed deck is, as already indicated; located above the imperforate portion of said feed deck. More important, the inlet passage or passages of the fan are located over the imperforate portion of th feed deck. The fan illustrated and thusapplied involves a fixed fan casing 53 with axial intake passages 54, both of which are located above the imperforate portion 53 of the deck, and a blade-equipped fan head 55' working in said casing. The fan casing 53 illus trated is provided with an air discharge spout 55'in whichis a damper 01" valve 55a by means of which the effective force of the fan can be controlled. Fan head 55 is carried by a transverse power shaft 56.

Secured to the framework and extended aboveand over the feed deck is a housing 51 preferably ofsheet metal and shown as enclosing the fan casing 55and as being provided with bearings 58 in which the power shaft 5% is journaled. Since-the outlet from housing 5'I-is through fan casing 53 havingits inlet passages'54 located over the, imperforateportion l3'of saiddeck, it may be said that the outlet or discharge passage or passages of the'housing 57' are located above the imperforate portion of the said deck. Shaft 55, at one end, is shown as provi'dedwith a pulley 59 over which will run a power-driven belt, not shown; that furnishes power for all of the running parts of'the machine. At'its oppositeend power shaft 56 is provided with a pulley 6%" over which runs the b'elt45. Belt45'ln the drawings is preferably of the multiple V-belt type.

Casing 57, in one or more of its side walls, is preferably provided with a transparent pane or window 6| through which the operations that are taking place within thev machine may be readily observed without actually, opening up, the casing. In Figs. 1, 3 and 4 I' have illustrated manually operable window wipers including blades 62 working; against the inner face of the transparent pane. and provided). outside of the casing with operating cranks .63;

To receive the particlesofthe mill' stock that are discharged laterally from the deck at the lower side thereof, the casing is provided with a long receivingspout 64 that leads to a long approximately cylindrical drum '65 having a discharge opening 66'. Working in the drum 65- is a rotarywing gate or feeder 61, the shaft 68 of which" is journaled' in the ends of the drum 65 and in suitable bearings on the framework. The receiving spout'fi l, the-drum 6 5, and its discharge opening 66', are divided into a multiplicity of compartments by partition plates 69;, see particularly Fig. l; and the'bladesof the feed gate 57 are correspondingly divided'by the partitions 69. Atthe'deliverypnd' of the machine; and located in position to receive from the imperforate portion l3 of the feed deck, is a receiving spout 10. see particularly Figs. 1 and 3. This receiving spout l0, much like the receiving spout 64, includes a drum-like portion H in which works a wing feeder or gate 12, the shaft 13 of which is connected by miter gears 14 to the shaft 68 of wing feeder 61.

The numerals 14, 15, I6, 11, I8 and i9 indicate flexible joint strips applied to the Various parts where they are indicated, in accordance with common mill practice in analogous cases.

Crank shaft 42, see particularly Figs. 2, 3 and 4, is provided with a small pulley 80 aligned with a larger speed-reducing pulley 8| journaled to a, shaft 82 journaled in suitable bearings on the main frame and provided with a smaller pulley 83. A belt 84 runs over the pulleys 80 and 8|. A transmission belt 85 runs over the pulley 82, over the heretofore noted pulley 50, over a pulley 86 on shaft 13, and against a belt tightening pulley 8T.

Operation The commingled farinaceous stock will, of course, be fed onto the receiving end of the vibratory feed deck, from the spout 41; and

under the vibratory movement of the deck the stock will be progressively fed longitudinally of the feed deck, while subject to the action of gravity which latter will cause the commingled stock to drift toward the low side of the said deck. The character of the vibratory movement of the feed deck and the manner in which the progressive feed of the stock is produced, is generally known and, briefly stated, such feed movement is produced by that part of the vibratory movement of the deck which lifts and projects the stock forward.

In the illustrated improved support for the vibratory feed deck, the character of the forward or progressive feed movement given to the deck may be modified by independent adjustments of the links I8, which link adjustments, as already described, may be produced by loosening of the hand wheels 26 and shifting the rods 23 in the segmental slots 24. The pitch or longitudinal inclination of the feed deck, as alreadynoted, may be produced by simultaneous adjustments of the beams 25 on their common supporting pivot shaft 27.-

The lateral inclination of the feed deck, note particularly Figs. and 6, may be varied by adjustments of the right-and-left threaded adjusting screws I1; and, of course, the greater the lateral inclination of the deck, the greater will be the tendency of the stock to drift toward the low edge of the deck.

Under endwise vibratory movements of the feed deck the heavier particles will be projected longitudinally farther toward the delivery end of the deck than will the lighter particles, and the lighter particles will travel faster and more quickly toward and off from the low edge of the deck. For example, with the machine shown, wherein the longitudinal catch drum or trough 65 is divided into three compartments by two partitions 69, the bran will be delivered into the first section, the middlings with attached bran into the second compartment, and the pure middlings or farina into the third or last section. of course, the number of these sections may be greater or less than illustrated in the drawings so as to make more or less fine divisions between the various particles of the stock.

It will, of course, be understood that in this improved machine the perforate deck or screen is not primarily used or intended for use as a screen proper and that the perforations therein are intended simply for the passage of air, to more or less lift and sort of fioat the stock on the vibratory deck. It has been quite generally assumed that the movement of the air through the perforations'of the screen or perforated feed deck must be produced by creating a blast above atmospheric pressure immediately below the screen. However, I have demonstrated in actual practice that this is not the best method or manner of producingthe flow of the air upward through the perforations or air passages in the deck; but on the contrary, that the purifying and. separating action can be improved by primarily producing partial vacuum or below atmospheric pressure immediately above the screen or perforated deck.

When sufficient partial vacuum or suction is produced immediately above the screen, air will, of course, be drawn upward through the perforations and that will produce also low pressure or pressure below atmospheric pressure immediately under the screen, and herein is found an important improved action in which the air drawn upward is moved to and through the perforations of the screen, in the form of myriads of upwardly converging air cones, each directed toward one of the perforations; whereas, an air blast directed against the bottom of the screen would tend to spread over the bottom of the screen and only finally be forced upward throughthe perforations,

It is not intended that any of the very fine particles, such as flour, would pass downward through the perforations of the deck or screen, but some such fine particles may get into or even pass downward through the perforations, but in that case, such fine flour particles will be immediately caught and picked up by the upwardly converging air cones and will be drawn back through the perforations tothe top of the screen; whereas, if such fine particles were thus picked up by a high pressure blast from below the screen, they would be more or less scattered against the bottom of the screen.

The improved action resulting from the suction or partial vacuum, both above and below the screen, also gives a better floating action to the stock on the screen, in that the lighter particles will be lifted or raised to the top of the floating stream of stock and sort of divided into strata in which the lighter trata will be lifted above the heavier and lower strata; whereas, if

the upward movement of the air was produced- ,by-high pressure below the screen, the air, iefore reaching the lighter portions of an upper stratum of the stock, would have to pass against and through the heavier particles of the lower strata.

The imperforate section or portion of the feed deck herein illustrated is also a very highly important and improved feature. In the machine described, some of the very light particles, such as dust, bees wings or fine bran particles, will be picked up by suction and carried over the rail 52 toward the intake of the fan, which latter, for an important reason, is located above the imperforate portion of the deck. When these relatively light portions, such as stated, reach a point over the imperforate deck portion, the upward draft or suction will be decreased and all or nearly all thereof will be precipitated on the said imperforate deck and discharged. therefrom into the transverse end spout l and from thence intodrumor catch troughlll The air drawn to the ianmay contain some very-lightdust, but. most of the light particles willbe precipitated anddischarged as just described.

The casing that encloses the space above the perforate deck is highly importantnot onlyfor the reason that it causes the-partialvacuum produced above the deck. to act'with maximum ef ficiency,v but prevents. outside air currentsfromv modifying or interfering ,with the operations pro-. duced within the casing. The transparent win.- dows, as is obvious, permit the operator to ob. serve the actual operation that are taking place. within the casing.

A commercial embodiment'of the inventionis illustrated in the accompanying: drawings, but it,wil1,, of course, be understood that various alterations and changes therein may be made within the scope of the invention disclosed and herein broadly claimed.

What I claim is:

1. In a machineof the kindldescribed, a casing, a fan having an intake opening from said casing and an outletdischarging outside of said casing, a perforate vibratory feed deck located-in said casing and having an imperforate portion located directly under the intake of said fan, said feed deck being laterally inclined for the selective transverse delivery of stock from the lower side edge of said deck according to the specific gravity thereof, meansfor vibrating said deck endwise to produce the feeding. action, means for receiving from the delivery end of the imperforate portion of saiddeck light particles carried over onto said imperforate portion by suction from said fan and:a raised bafiie' marking the line of division between the perforate and imperforate deck portions.

2'. In a machineof thekind' described, a per forate longitudinally vibratory'feed deck laterally inclined for transverse drifting. and delivery of the commingledstock-toward the lower side edge thereof; means located; above said deck and operative simultaneously to producepartial vacuum; both above and-=below the perforatedsurface of said deck, the partiaL vacuum produced above. said. deck. being. somewhat, greater than that produced ,below. said; deck so as: to produce.

an.upward;movement of air through. the perforated feed, deckhand stock,. the. character of.

; theperforatedfeed; deck and the velocity of'air movementnpwardly therethrough being such that classification. and. separation of the commingled stock will be accomplished entirely,

above the vibratory deck; in further combination.with. laterally spaced. intermediately pivoted beams, afshoe mounted for. endwise vibratory movements on. said beams, said. perforate feedv deck being .mounted on.,said shoe, mean for. the delivery. of commingledstock onto the receiving 5 end: of said deck,. and in, further combination with a casingenclosing the space above said'deck, said, deck; having an imperforate portion located directly under the intake of said partial vacuum producing meansanda raised bafil'e marking the linehof-ldivision,betweenthe perforate and im perforate deck portions.

3. In a machine ofthe kind described, a oasing, a fan having-anintake opening from said casing and an outlet discharge outside of said casing, a perforatelongitudinally vibratory feed deck located in said casingbelow the intake of said fan sOihat air moved by said fan will pass upwardly through said feed deck, said feed deck being laterallyinclinedfor the selective transverse delivery ofstock toward the lower edge of said deck; andmeans for selectively receiving the stock'from. the lower side edge'of said feed deck progressively and according. to specific gravity thereof, the-character of the perforated feed deck andnthevelocity of air movement upward'. therethrough being such that the: classification and separation: of thecommingled stock will be accomplished entirely above the vibratory. deck, said deck having an imperforate portion located directly under: the intake ofo'the: fan and having araise'd'raili following the line of division. betweerr thev perforate and imperforate portions of the: deck.:. 7

4i Thestructure defined. in: claim 3 inwhich the saidraised railuextends diagonally of the feed deck from its upperreceiving endportion towarditslower delivery end portion.

ROBERT J S. CARTER.

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