US 3188144 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
June 8, 1965 Filed April 9, 1962 B. GMUR ETAL BIN DISCHARGE MEANS 4 Sheets-Sheet 1 IN ve/vTo/25 aku/va 6mm HANS QETIKER- ArronkEs s J 8, 1965 B. GMUR ETAL 3,188,144
BIN DISCHARGE MEANS Filed April 9. 1962 4 Sheets-Sheet 2 June 8,1965 GMUR HAL 3,188,144
V I BIN DISCHARGE MEANS Filed April 9, 1962 4 Sheets-Sheet :5
IN VENTORS 25 sea/v0 6/16/62 53 HANS OET/KER 55 I gw Fm ATTORNEYS June 8, 1965 s. GMUR ETAL 3,188,144
BIN DISCHARGE MEANS Filed April 9, 1962 4 Sheets-Sheet 4 (NVEN TORS BRUNO C-Mi/n HA/vs OET/K'ER BY: I
ugew d Tm Afro/Quays W- it United States Patent 3,188,144 BIN DISZCHARGE MEAN Bruno Gmiir and Hans Getilrer, both of St. Gallen, Switzerland, assignors to Gebrueder Buehler, Uzwil, Switzerland, a firm of Switzerland Filed Apr. 9, 1962, Ser. No. 186,120 Claims priority, application Switzerland, Apr. 12, 1961, 4,296/61 19 Claims. (Cl. fill-29) Our present invention relates to improvements in discharging means in silo bins for pulverous or granular freeflowing goods, and the objectives of the invention are to provide first an even and uniform delivery, as far as possible without bridge formation in the goods, second a delivery in accordance with a pre-set program following the principle of fluidization of the goods with the aid of air or other gases in a manner free of dust, bridges and clumps, third a minimum power requirement and mechanical or structural expense, fourth a high goods quality and selective constant mixability, fifth subdivision of the bins.
Various mechanisms and arrangements have been proposed before for draining pulverous or granular free-flowing goods from silo bins with a view of attaining a uniform discharge without, as far as possible, the formation of bridges. Such known mechanisms and arrangements preferably operate by mechanical or pneumatic ancillary means. All of these known devices, however, have disadvantages. In the case of pneumatic means, these disadvantages are uncontrolled delivery and lowering of the goods level, which leads to the formation of chimneys directly above the outlet and, thus, to segregation. In the case of mechanical means, on the other hand, these disadvantages are, above all, frequent consolidation of the goods, unintentional outflow and discontinuous delivery.
We attain the objectives mentioned above by the combination of mechanical and pneumatic means shown in a plurality of forms in the drawings, in which- FIG. 1 is a vertical section through an asymmetric bin of a first form,
FIG. 2 is a vertical section through an asymmetric bin of a second form comprising a pivotable bottom portion,
FIGS. 3 to 6 show a third form, FIG. 3 being a vertical section through a symmetric bin on the line IIIIII of FIG. 4 and depicts the mode of operation of the delivery means, FIG. 4 being partly an elevation and partly a vertical section on the line IVIV of FIG. 6 of a bin, FIG. 5 showing in section a valve for pressure-fluid servocontrol, and FIG. 6 showing in plan and on the line Vl-VI of FIG. 4 a bin with the field subdivision and the control scheme, the various conduits and control lines being drawn apart for the sake of clarity,
FIG. 7 is a vertical section through a fourth form of the invention and illustrates the fundamental use of a plurality of roof inserts in large symmetric cells or bins,
FIG. 8 is a further vertical section through a fifth form, illustrating the fundamental use of a plurality of roof inserts in large asymmetric bins,
FIG. 9 is a vertical section through a sixth form, illustrating the fundamental use of a roof insert adjustable in various respects,
FIG. 10 is a section through a valve for electric servocontrol, which is a modification of the valve shown in FIG. 5, and
FIG. 11 is a partial vertical section through an airmetering device of the second form.
3,188,144 Patented June 8, 1965 Like reference signs in the various figures designate like or similar parts and portions.
The goods 9 are deposited in a bin 10 extending at right angles to the plane of FIGS. 1 and 2 and compris ing walls 11, a cover 12 and an inclined bottom 13. To the latter is associated a delivery means which here is formed as collecting channel 16. The goods 9 are fed into bin 14] through a device 17.
The bottommost portion of bin floor 13'adjacent to channel 16 comprises a plurality of porous elements 18 arranged as ceiling of a ventilation chamber 19. Channel 16 as well as the elements 18 are covered by an inclined insert 20 which extends over the entire length of bin 1t leaving free an elongated slot 21 between insert 20 and bin bottom 13.
Chamber 19 along slot 21 and by means of webs 22 disposed in an airtight way and manner, is subdivided into a plurality of ventilation fields which may be charged individually with air or some other suitable gas through a common air conduit 24 and valves 25. The chamber 27 formed below the inclined insert 20 through a wasteair line 23 is connected to a dust separator 29.
Channel 16 may be of any known construction. In the present case, porous elements 30 are disposed above a chamber 32 which is fed with air through a ventilation system 31, both channel and elements 30 being inclined. To channel 16 is associated a goods-level sensing member 33 which comprises a membrane 34 and a switch 35 in a casing 36. With this arrangement, the mode of operation is as follows.
As it is required that the goods 9 shall not be delivered into channel 16 in an uncontrolled way and manner, the inclined bottom 13 with the porous elements 18 is to be so covered by the inclined insert 20 that the slope of the bottom 13, the size of slot 21 and the width of coverage by insert 20 opposite the porous elements 18 of bottom 13 is fitted to the angle of slope or repose of the goods 9 so that the latter cannot advance to channel 16. By ventilating one of the fields in chamber 19 and by the passage of this air or other suitable gases through the elements 18, the goods above the respective field are fluidized whereby the goods flow like a liquid into channel 16. The respective field to be ventilated is selected by the controllable valves 25 which are disposed between conduit 24 and the fields of chamber 19.
By sloping the channel 16, a furthergoods transport on the basis of fluidization is possible via the elements 18 to a tapping station such as a sluice. The level-sensing member 33 associated to channel 16 serves for controlling the fluidization of the goods to be discharged and ensures the formation of and maintenance of an air cushion in space 27. This air cushion is formed in space 27 by the fluidization gases which accumulate here. Thereby is prevented a clogging of the delivery device, which results further in a uniform outflow of a type of goods of higher quality. By virtue of the chosen subdivision of the entire bin-length into a plurality of fields, ventilation may take place according to any suitable program which advantageously will be more fully explained in a form of invention to be described later on and which allows of any desired mixability and lowerability which, however, are continuously controlled.
The air cushion in space 27, which is always present, serves as a first dust separator of the fluidization gases. Further, said space through a waste-air conduit 28 communicates with a dust separator 29 and thence with the outside air.
It may be desirable to use the bin alternatingly for goods of different angles of slope or repose. This requires a bin bottom which is adjustable at least in its lowermost portion, whereby the width of slot 21 also becomes adjustable.
FIG. 2 shows one possibility for realizing this requirement. The goods here are again in a bin formed by walls 11, a cover 12 and a bottom 13, the goods being charged into the bin through a feed conduit 17. The lowermost portion of the bin bottom is pivoted on a pin 30 to said bottom and is ventilatable through an air conduit 24, controllable valves 25, a piece of rubber hose 39, chamber 19 and porous elements 18, and is adjustable in slope. Slot 21 thereby is adjustable in width, as shown by dash-and-dot lines, and thus may be adapted to the angle of slope or repose of the goods. Further delivery is effected in the fluidized manner described above, into channel 16 with the porous elements 30 above chamber 32 and the ventilation system 31, and is supervised by the level-sensing member 33. The air cushion constantly maintained in space 27, through the waste-air line 28 communicates with the upper bin space 40 which here serves as a second dust separator, following the dust separation in space 27. The efficiency of the device may be still further increased with the aid of an aspiration device comprising an air conduit 26 leading from space 27.
The mode of operation of the form of invention shown in FIG. 2 is similar to that of the first form shown in FIG. 1, but involves said important advantage of adaptability of the fluidization means to the angle of slope of the goods 9 and a possibility of the evacuation of space 27.
By combining two bins as shown in FIGS. 1 or 2, the bin may be made symmetric with respect to the collecting channel 16 which, as mentioned before, may be of any suitable known construction and in the present case is formed as inclined fluidizing gutter. Such construction has proved extremely practical and shall serve as basis for the details yet to be described further on. In this connection, however, the mode of operation described above is substantially adhered to and further improvements are provided for increasing the economy and simplicity of the discharge of the bins under discussion.
Said combined construction is shown in FIGS. 3 to 6. Here again, the goods 9 are filled into a bin 10 formed by sidewalls 11 and two inclined bottoms 13 on both sides of a collecting channel 16, the entire bin bottom thus forming a V. The inclined bottoms are subdivided over the entire bin length and width into fields 101 to 120 (FIG. 6) by webs or partitions 22 which are disposed airtight in chambers 19, and said fields again are covered 'by porous elements 18 towards the bin interior. The two inserts, which in FIGS. 1 and 2 are denoted by 20, are joined, thus covering the lowermost portion of the chambers 19, i.e. the fields of even number from 102 to 120 (FIG. 6), and the intermediate collecting channel 16. The latter is inclined, together with the porous elements 30 (FIG. 3) which through a ventilating system 31 and a chamber 32 are swept by gases. Said channel 16 feeds a sluice 41 (FIG. 4). Thereby is formed a V-shaped insert 42 having an upwardly pointing tip. By providing intermediate webs or partitions 22 in insert chambers 43 and a cover with porous elements 44, said insert 42 is subdivided into a plurality of fields, as shown by the evennumbered'fields 124 to 140 in FIG. 6. In the tip of insert 42 is disposed a flashing 45, and said insert is held on guides 46 and these again are supported on horizontal braces 47. FIG. 4 shows this arrangement in a further elevational and sectional View.
The fields in the bin bottoms 13 are ventilated with the aid of perforated tubes 40 (FIG. 3) which are partly maskable by tubes 49 telescopable thereon, said tubes being disposed downstream of controllable valves 25. At .the same time, the fields formed in insert 42 are charged with air through conduits 50, as shown in FIGS. 3, 4 and 6. For the entire ventilation is provided an air conduit 24 in which is inserted a main valve 51.
A first form of the valves 25which serve for the selective ventilation of the various fieldsis shown in FIG. 5 and comprises a valve casing 53, two feeding branches 54 and at right angles thereto a consumer branch 55 which extends far into casing 53. Opposite to branch 55 is provided a membrane 56 clamped between a valve cover 57 and the casing 53. Said membrane by a servo pressure fluid acting through a pipe 58 may be sagged toward-s branch 55 to shut-off same.
For emptying the bin and considering a definite program, a collective or bus control is provided of which the fundamental features are shown in FIG. 6. A ventilating pump 60 via main valve 51 feeds conduit 24 and, via controllable valves 25, feeds the various fields of bin 10, ventilation taking place through the conduit system 48 to 50 shown clearly in FIGS. 3 and 4.
To prevent channel 16 from becoming clogged, a control is made with the aid of level-sensing member 33 which via a pair of lines 62 is connected to a controller 63 and a unit 64 for controlling main valve 51. To fulfill a particular delivery program, a selective control unit 66 is provided which controls the valves 25 via lines 67. Such control may be carried out by a pressure means, whereby pump 60 via an air conduit 69 communicates with unit 64 and unit 66. The mode of operation of the arrangement set up in accordance with FIGS. 3-6 permits to take into consideration different mixing requirements and level-lowering tendencies of the goods in the bin. The following description is restricted to a half bin as shown in FIG. 6 but also is applicable to a bin as shown in FIG. 4, i.e. to a bin comprising two inclined collecting channels 16 on both side-s of a sluice 41.
The goods are filled into a bin 10 comprising walls 11, ventilating chambers 19 with partitions 22 for subdivision into bottom fields 101 to and porous elementslfi disposed above same. The V-shaped insert 42 covers the.
lowermost parts of the inclined bin-bottom halves 13 and the intermediate channel16 with its porous plates 30 above chamber 32. The goods filled-in slide over a certain distance towards channel 16, depending on the inclination of bin bottom 13, the width of the elongate slot 21 and the angle of slope or repose of the goods, but never reaches channel 16, as shown in FIG. 3 on the lefthand portion thereof. For delivering the goods 9, a bin field is selectively ventilated which always comprises three congruent fields of the ventilation chambers 19 and 43 in the one half-portion of bin bottom 13 and in the one half-portion of insert 42, for example the fields 101, 102 and 122. At the same time, the porous elements 30 in channel 16 also are ventilated. Thereby the goods 9 become fluidized and flow off, like a liquid, into sluice 41, as shown in the right-hand portion of FIG. 3. In order to permit to meter the ventilating air in the two fields of bottom 13, the perforated tube 48 in the lower field 102 is partially maskable by a second tube 49 which leads into field 101. The fluidizing air then collects above channel 16 and below insert 42 in space 27 where a first dust removal takes place, and then escapes through wasteair conduit 28 into the upper bin room 40 where a final dust removal is possible.
When more goods flow from bin 10 through slot 21 into channel 16 than sluice 41 can swallow, the membrane 34 of the level-sensing member is sagged outwardly by the pressure of the superjacent goods, switch 35 is actuated and thereby main valve 51 closed via line pair 62, the two units 63, 64 and control line 65, whereby ventilation of bin bottom 13 and of insert 42 is interrupted and the flow of goods ceases. Thereby channel 16 may be discharged by sluice 41, without replenishment from bin 10, until switch 35 of level-sensing member 33 is opened again, whereupon ventilation of the three fields 101, 102 and 122 is resumed.
In order to attain certain mixtures or level lowering tendencies of the silo goods, a special delivery program through selecting control 66 may be used. Such control permits to ventilate a corresponding field combination for a limited period of time and, for example a cyclic sequence of the field combinations to be ventilated, for example the combination 101, 102 and 122 is followed by 103, 104 and 124 and so on to the combination 119, 120 and 14th, or any other desired sequence. Thereby, for example, compressed air is delivered from pump 60 through conduit 69 via unit 64 and the selecting control means to the valve control lines 67 and, through same, to the valves 25. All of the valves 25 of the field combinations which do not have to be ventilated, thereby are charged with compressed air, while the valve of the field combination to be ventilated is free of compressed air. In this control arrangement, the valves 25 according to FIG. 5 operate so that, when a valve is closed, the ventilating air may pass on both sides of branch 55 to the next valve, while when the valve is open, the ventilating air flows through branch 55 to the field combination. A further feature of the control arrangement is that each response of the level-sensing member 33 stops the timer of the selecting control 66 so that always the desired efiective period of ventilation acts on to a field combination and the required program is maintained thereby.
Since pump 60 may be used both for ventilation and control, two separate pumping systems are provided therein, namely a lower-pressure portion for ventilation and a high-pressure portion for control. Although not shown in the drawings, the ventilation of channel 16 is connectable to pump 60.
As shown by experience, no further subdivision into said individual fields is necessary in the bin itself, apart from the subdivision of the chambers 19 and 43 by means of webs or partitions 22, since the latter sharply define the various fields to be ventilated and there are no straying or scattering effects in both directions of the elongate slot 21. The fields opposite and adjacent to channel 16 are influenced just as little.
When some fields of the bin are empty, quick changeover is efiected by the level-sensing member 33 to a nextfollowing field without any interruption of the delivery program, and the result is an economical meet the system.
The use of several V-inserts, as shown schematically in FIGS. 7 and 8, is particularly suited for large bins.
A first insert 42 is spread out on or overlaps channel 16, as before, and the lowermost portion-s of the ventilatable bin bottom 13 formed by ventilation chambers 19 and porous elements 18 on both sides of channel 16. Above the slots 21 between the porous elements 18 and 44 again are disposed further V-inserts 42' with new slots 21' between the porous elements 44' of the inserts 42' and the porous elements 18 and 44, the number thereof always being adapted tothe bin sizes.
The ventilation chambers 19, 43 and 43 again are subdivided through webs 22 into individual fields which are put together to individual field combinations through the conduits 48, 48, 49, 49', 50, 59' and 50". Further, chamber 19 of bottom 13 through partitions 70 is subdivided into partial chambers, according to the number of the additional inserts 42. The ventilation system, thus, also is subdivided. Controllable valves 25, 25' are fed through an air conduit 24 and thence, as desired, through valve 25 the conduits and pipes 48, 49, 50 and 50' or, through valve 25', the conduits and pipes 43', 49' and 50". The conduits 48, 49, however, only ventilate the lower partial chambers separated by the webs 70, while the conduits 48, 49 have to ventilate the upper as well as the lower partial chambers, i.e. the entire bin bottom 13.
The mode of operation is fundamentally similar to that of the arrangement described above. Owing to the larger number of fields in bin bottom 13 and in the inserts 42 and 42', a greater number of valves 25, 25 are required. The selecting control system thus is given a larger range of control possibilities which, however, requires no change of the principle.
A bin construction as shown in FIG. 8 may be used for taking into consideration certain matters of space and the like. By reason of the asymmetric arrangement of channel 16 in bin bottom 13-, the inserts 42 and 42 which themselves are symmetric, also have to be arranged asym metrically.
The forms of construction shown and described may be enlarged, as desired, by using V-shaped ventilated or non-ventilated inserts or inserts inclined to one side only, in symmetric and asymmetric bin layouts with elongated collecting channels, without deviation from the principle underlying the invention.
As shown in FIG. 9, the entire delivery arrangement on both sides of channel 16 and above same may be adapted, by means of a V-shaped insert 72 which is adjustable in inclination and height and/or width of overlap, to the angle of slope or repose of the silo goods.
Above bin bottom 13 which is formed of ventilation chambers 19 with webs 22 and porous elements 18 and in which for ventilation purposes are provided perforated pipes 48 and telescopable pipes 49, is disposed a V-insert 72 which is adjustable in the manner described. The porous elements 76 with subjacent webs 22 and ventilating chambers 77 are pivoted, on pins 75, to a guide sleeve 73 which is movable on a guide rod 74 and clampable thereto. For altering the width of overlap, further elements 78 above ventilating chambers 79 with webs or partitions 22 are adjustably associated to the porous elements 76. The inclination of the insert is set, for example, by a sleeve 80 which is movable on guide rod 74, via journal bearings 79 on sleeve 80 and chamber 77 and via straps 81 on to the adjustable V-insert 72. Ventilation is effected through rubber hoses 86. The apex of insert 72 is provided with a cover or flashing 45. An adjusting member projecting from hte bin is provided in guide rod 74 for setting the inclination.
The mode of operation of this further construction is similar to the one described above, but has the advantage that it is adaptable at any time to the angle of slope or repose of the silo goods by adapting the delivery means associated to channel 16 to said angle.
FIG; 10 shows a second example of the controllable .valve 25. In a valve casing 53 are provided ports 54 for feed-in and an outlet port 55 disposed at right angles thereto. The mouth 82 of port 55, which is facing the elastic membrane 56, is slightly funnel-shaped and is closable by means of a tapered valve head 83 on the other side of membrane 56. An electric servo-system 84 which trough lines 85 is connected to a selecting control unit 66, may be used for actuating the valve head and, thus, valve 25.
FIG. 11 shows simplified means for metering the ventilation air in the chambers 19 which are subdivided into a plurality of fields by webs or partitions 22, which means take the place of the perforated tubes 48, 48' and the tubes 49, 49 telescopable thereon. On perforated tubes 48, 48' with perforations 87, pipe clips 88 are movable which are fixable in a certain position by clamping means 89. In order to render the clips 88 readily accessible, holes 90 are provided in the chambers 19. Said holes 90 are hermetically closable by plates 91 of elastic or resilient material which are firmly pressed down on the holes with the aid of disks 92, counterdisks 93 and clamping screws 94.
The fundamental bin forms described above with reference to FIGS. 1, 2 and 3, 4, 6 may be varied in many Ways and respects so as to realize wishes as to adaptability to structural details and questions of maintenance, service and supervision, without, however, changing the objective of the invention nor stepping out of the range of the invention as defined in the appended claims.
By all these possible arrangements, the system disclosed by the present invention attains the goal and ob- 1. In a device for discharging pulverous or granular goods from bins via an inclined bin bottom into an elongate collecting channel, the improvement comprising a generally upright bin having an inclined bottom supporting fluent material in the bin, an elongated collecting channel extending along the lowermost portion of the bin bottom to receive material flowing downwardly over the bin bottom, an inclined insert overlapping the lowermost portion of the bin bottom adjacent said channel, said insert being inclined oppositely to the inclination of the bin bottom and forming with the bin bottom a relatively narrow delivery slot, the inclinations of the bin bottom and said insert, and the width of said slot, being so coordinated with the angle of repose of the fluent material on the bin bottom that, in the absence of ventilation, the material on the bin bot-tom will remain at rest, and a plurality of porous elements and of means forming ventilation chambers comprising the lowermost bin bottom portion below said insert, said lowermost bin bottom portion being subdivided longitudinally of said slot into a plurality of ventilation fields.
2. A device as set forth in claim 1, in which the lowermost bin-bottom portion, which is overlapped by said inclined insert, is adjustable in slope.
3. A device as set forth in claim 1, in which the bin bottom is generally V-shape and said collecting channel constitutes the apex of the V, and including two of said inclined inserts overlapping said channel and each overlapping the ventilatable portion of the associated bin bottom half adjacent the channel, each insert forming one of said slots with the associated bin bottom half, the two inserts conjointly having an inverted V-shape.
4. A device as set forth in claim 3, including further similar inserts disposed outwardly of said first mentioned slots and forming additional slots with the associated bin bottom halves.
5. A device as set forth in claim 1, including perforated telescopable pieces of tubing for ventilating the ventilation chambers and thus the fields.
5. A device as set out in claim 1, including perforated pipes for ventilating the ventilation chambers and thus the'fields, and pipe clips adjustably masking said pipes.
7. A device as set out in claim 1, in which the inclined insert is adjustable in height, inclination or in the width of overlap.
3. A device as set out in claim 1, in which the entire bin bottom is ventilatable through porous elements and including webs, mounted in airtight manner and at right angles to the slot, subdividing said'bin bottom into a plurality of ventilation fields disposed in adjacent relation.
9. A device as set out in claim 3, including porous elements ventilating said insert, and means forming ventiadjacent relation.
11. In a device for'discharging pulverous or granular goods from bins through an inclined bin bottom into an elongated collecting channel, the improvement comprising a bin having an inclined bin bottom supporting fluent material thereabove in the bin, a channel extending along the lowermost portion of said bin bottom to receive material therefrom, an inclined'insert overlapping the lowermost portion of the bin bottom adjacent to said channel, said insert being inclined toward said bin bottom in a direction opposite to the inclination of said bin bottom, said insert and the bin bottom conjointly forming a relatively narrow delivery slot, a plurality of porous elements and means defining ventilation chambers forming said lowermost bin bottom portion below said insert, said bin bottom portion being subdivided into a plurality of ventilation fields along said slot, said entire bin bottom portion being ventilatable through said porous elements, said ventilation chambers being divided by a plurality of webs mounted in an air-tight manner at right angles to said slot, and forming said plurality of ventilation fields disposed'one adjacent the other, said inclined insert including ventilatable porous elements and means forming ventilation chambers subjacent said porous elements and subdividing said porous elements into ventilation fields at right angles to said slot, said fields formed in the ventilation chambers in the bin bottom and in the inclined insert being substantially congruent whereby the bin bottom is subdivided at right angles to said slot into a plurality of ventilatable bin strips disposed one adjacent the other, and a selecting control system for selectively ventilating said ventilation fields, which latter are provided at right angles to said channel and in substantially congruent relation in the same position relative to said slot in the bin bottom and in the inclined insert, and a common feed conduit for said ventilation chambers, provided with selectively actuable valves therein associated with the respective groups of ventilating fields for the purpose of ventilation.
12. A device as set out in claim 11, in which the valves are T-shaped and the diametrically opposite feed ports thereof are provided for connection to the feed system and the opening disposed at right angles thereto is provided for connection to the consumer-to be supplied, an elastic membrane being associated to the consumer connection in opposite relation thereto, and a servo-system being disposed for actuating the membrane on the side remote from said opening for closing the latter.
13. A device as set out in claim 12, in which the consurner connection disposed in the valve is funnelshaped, a valve head coacting with said opening is disposed on that side of the membrane which is remote from said opening, and a servo-system is provided for actuating said valve head.
14. A device as set out in claim 1, including a levelsensing member disposed in the collecting channel for acting on the air supply to the fields swept at any one time.
15. A device as set out in claim 11, in which a controllable main valve is provided in the feed system.
16. A device as set out in claim 15, in which the selecting control means is adjustable for programing the bin discharge, and controls the valves automatically, and a level-sensing member in the collecting channel acting on said selecting control means.
17. A device as set out in claim 15, including a control means for the main valve, and a level-sensing member disposed in the collecting channel and actuating said control means for the main valve.
18. A device as set out in claim 1, including a wasteair line which extends from the space under the inclined insert to a dust separator.
19. In a device for discharging pulverous or. granular goods from bins through an inclined bin bottom into an elongated collecting channel, the improvement comprising a bin having an inclined bottom supporting fluent material thereabove in the bin, an elongated collecting channel extending along the lowermost portion of the bin bottom to receive material therefrom, an inclined insert overlapping the lowermost portion of the bin bottom adjacent the said channel, said insert being inclined toward the bin bottom in a direction opposite tothe inclination of the bin bottom, said insert and said bin bottom conjointly forming a relatively narrow delivery slot, a plurality of porous elements and means defining 9 ventilation chambers forming said lowermost bin bottom portion below said insert, means subdividing said bin bottom portion into a plurality of ventilation fields along said slot, the topmost portion of said bin being a dust separator, andaspiration means connected to the topmost dust separator bin portion.
References Cited by the Examiner UNITED STATES PATENTS 7 832,400 10/06 Lyons 222459 2,278,701 4/42 Karr 30229 X 2,366,075 12/44 Weyandt 222-65 RAPHAEL M. LUPO, Primary Examiner.
LOUIS J. DEMBO, EUGENE F. BLANCHARD,