US2580823A - Nozzle construction for use in the pneumatic handling of flour and the like - Google Patents

Description

NORBOM Jan. 1, 1952 R NOZZLE CONSTRUCTION FOR USE IN THE PNEUMATIC HANDLING OF FLOUR AND THE LIKE 2 SHEETSSHEET 1 Filed Ayg. 8, 1950 Jan. 1, 1952 R. A. NORBOM NOZZLE CONSTRUCTION FOR USE IN THE PNEUMATIC HANDLING OF FLOUR AND THE LIKE 2 SI-IEETS-SHEET 2' Fil ed Aug. 8', 1950 45 m\ ow mm mm \EE mm mm omg 1 5 8 I Qv. rm g g rfimc wn H w M A m 9 NM v i Q S fi l 5 mi 2 z 0H N m 3m entor BagnarANor-bom (Ittorneg Patented Jan. 1, 1952 NOZZLE CONSTRUCTION FOR USE IN THE PNEUMATIC HANDLING OF FLOUR AND THE LIKE Ragnar A. Norbom, New York, N. Y., assignor, by mesne assignments, to B. F. Fitch, Newport,

' Application August 8, 1950, Serial No. 178,306

7 Claims. 1

This invention relates to the handling of finely divided bulk material, and more particularly to improvements in a suction nozzle for the discharge of the contents of a container by a pneumatic conveyor system. A nozzle of the type with which this invention is concerned comprises an extensible metallic tube, mounted in a horizontal position exteriorly of a container, and adapted to be extended through an end Wall of the latter and reciprocated along the bottom wall of the container, from end to end thereof. Nozzles of this type are shown and described in detail in U. S. Patents Nos. 2,440,379 and 2,502,740 and in my copending application, Serial No. 101,153, filed June '24, 1949, now U. S. Patent No. 2,523,229. Suchnozzles are adapted to handle those pulverized, granular, or powdered materials that are susceptible of being conveyed in an air stream, but are particularly employed for discharging flour, and similar granular or finely divided comestibles, from cargo vehicles or storage bins.

- Although the nozzle head disclosed in the aforementioned Patent No. 2,502,740 minimizes dusting of the material being handled and although the nozzle moves at a relatively slow rate (12 ft./min.), the pneumatic handling of certain types of powdered material, and flour in particular, is subject to an explosive hazard. Under some conditions the suspension of flour particles in air forms an explosive mixture which a chance spark or excessive frictional heat might ignite. When foodstufis are handled, lubrication of the metal-to-metal sliding contacts to eliminate excessive frictional heat is impossible because of both the resulting contamination and the possif bility of clogging the nozzle. Reduction'of friction by combinations of various metal-to-metal bearing contacts or sliding surfaces imposes the difficult problem of avoiding metals which are toxic.

Still another problem has developed in the use of the nozzle head shown in the previously mentioned Patent No. 2,502,740. The extensible portion of nozzles of the type under consideration comprises two spaced concentric tubes. The inner tube forms the suction discharge conduit while the space between the inner and outer tubes forms a duct for conveying material entraining outside air to the intake end of the nozzle. It is desirable that the inner tube be removable from theentireassembly for periodic inspection, cleaning, etc. In the construction shown in the aforementioned Patent No. 2,502,- 740, however, the inner and outer tubes are welded together at their forward ends, thus rendering removal of the inner tube impossible.

' Hence, it is an object 'of this invention to pro vide an extensible suction nozzle, of the type underconsideration, with long-wearing, non-toxic, non-metallic bearings having'low frictional resistance, and consequent low bearing temperature, at all points of sliding contact of the nozzle parts. r I

It is another object of this invention to provide a suction nozzle of the type under consideration with a readily dismantleable extensible portion.

Other objects and advantages of the invention will be evident from the following description and accompanying drawings in which:

Figure 1 is an elevational view, partly in section, of a suction nozzle embodyin this invention. The nozzle is shown in operative relationship with a container, only a portion of which is illustrated;

Figure 2 is an enlarged spending to Figure 1; l

Figure 3 is a sectional view taken on line 3-3 of Figure 2;

Figure 4 is a sectional view taken on line 4-4 of Figure 2;

Figure 5 is a fragmentary exploded perspecsectional view corretive view illustrating portions of the forward end (Figure 6), which converge downwardly to a generally rounded trough 1-3 disposed centrally along the bottom of the container. Projectinglsnugly through an opening 14 in the lower. portion" of one end wall H, and resting in the trough I3, is

the extensible portion 15 of anelongated tubular suction nozzle of steel, or other appropriate metallic material. Suitable mechanism (not shown), such as that describedin the aforementioned Patent No. 2,440,379 and Patent No. 2,523,229, is connected to'the extensible portion l5, exteriorly of the container, for effecting re ciprocation'thereoffrom one end of the trough l3 tothe other, in' order to withdraw the contents of the container by suction. I'he extensible portion of the nozzle comprises a pair of concentrically-arranged spaced tubular conduits l6 and 11, respectively, which are secured together at their forward ends, i. e. at the intake end of I3. TheJearwardiendTHof the tub'el 8 is adapt- 4 ed to have connected thereto the suction hose (not shown) of a pneumatic conveyor system.

The inner conduit I6 is of smaller diameter than the tube I8 and has sealing engagement therein, as later described. The outerconduit IT' is of somewhat greater diameter than the tube 18 so that the annular space betweemtheouten conduit and the tube and betweenithezouter'cone duit and the inner conduit I6 (when the nozzle is extended) forms a duct 2I havinggitsrearwardt end in communication with the atmosphere, exteriorly of the container, in order to supply-ma+ terial-entraining air to the nozzle head.

The; extensible: portion. I5; of: the. nozzle'lmay, be supported. for reciprocatingemovement by meansssof rollers: 22: (Figure. 1), one-mounted; on eachc siderof the-outer conduit. II: adjacentlthe rearward end :thereof. andriding; on longitudinal fixedguide-rails=(notshown).. One ormore fixed rollers-23 (Figure 1). also may be mountedrbee neatlr the outer: conduit :I Irexteriorly of the container ill and adjacent its end wall I I for support-e ingithe extensible portion of :the nozzle whereit enters-"the container. Mounted inthetloweriportion ofthe fixed tube I8 are two spaced longitudinally-extending; rub strips: or: slide bearings: 241 which. bear against thezundersideofwthe :inner conduit for "supporting the same. These strips-24; which-arashown best insFiguret3, preferably: are-.-- of. a synthetic :linear pol-yamide'pcommonly knownas nylon, which has the excellent:bearingiproperties ofhig-hload-care ryingicapacity and reducedwfrictional resistance,- with consequent little development of heat... N-y lon: also is non-toxic: Thee rub. StYipSx 2M are clamped in channels 25 that armwelded orlotherwise suitably secured :to metalliczplates 2%. These latter are bolted at their ends, or otherwise=suitably secured, .to. thefixed tube. I3.

Mounted within the forward end of the fixed tube: I8risa'a generally-annulan'sleeve bearing: 21,

also of nylon.v Thez-innensurfaceofi thersleeye bearing 2'. is cylindrical: and: snugly; embraces the "outer: surface: of the-inner conduit I6; The outer surface of the sleeve bearingfllisawnvex in' longitudinal orraxialisection; asushovm siniEi'gure' 2, so. the bearing: makes substantially 'line contact with1the innerrsurface: of; the; fixed tube I 8. This construction. permits :free: and l easy re.- cirprocation. of: the: inner' conduit? I3 withinthe tube: I85 even: though: slight misalignments: occur:. Additionally, thesleeve-bearing; 21;- forms a: closure: or'seal for: the .annularrspace between the: innerr conduit: I6" and: thefixed tube: I8: to prevent. bypassing 1 suction from .the. nozzle: head; The-forward endfof the fixed tube Wis-supported onitwospacedbearingblocks 2'8; (Figurerr): also of nylon; which rest'on: ther-inner' surface of: the outen'conduit Is'I The "upper; portions'of the blocks 2&areprovidecl with? lugs 29-.which1extendirathei'. loosely through aperture& in; the wall: on the fixed tube It and. project: rather. loosely into corresponding recesses in? the: sleeve bearing; 2], to=thusrretain both .thesbearing- 7:! and the-blocks 28in operating position; Additionally; this con.- struction of the bearing; and3 the blocks" renders them a bothself-adjusting: to any surface irregularities on misalignments. 7

Preferably the bottom of the trough I3 is provided with a nylon strip 30 (see Figure 6) of corresponding transverse curvature and extending from end to end thereof for supporting the extensible portion I5 of the nozzle during its reciprocating; movement-.within ther container- I 0. This strip-3m preferably is secured Within. the trough by both nylon screws 3I and appropriate cement, although other suitable securing means may be employed. Similarly secured to the upper side of the rearward-end-of" the inner conduit I6 is a nylon padi32; (Figure 2) for engagement with the inner surface'ofthe fixed tube I8 to prevent metaleto-metal-contact, in the event such end 'of'rthezinner. conduit is upwardly displaced for any reason.

Because. nylon is of that class of materials which under-some circumstances develop static chargesz of electricity upon being rubbed, it is highly desirable that all metallic parts in rubbing contact. with. the various.- nylon; bearings;- be grounded. in. some appropriate manner. Such: grounding; completelyeliminates any possibility; of a spark:bytstatic-ldischarge..

The upper: portion of. the. nozzlev head isv sub-- stantially. the sameassthat shown. in the afore: mentioned Patent No. 2,502,740. The-lower-pprr tion,- however, is. of somewhat different construction, AsshoWnbeSt-inFigureS-Z and-5, the. lower half of the forwardrend:ottheinner. conduit I6ris terminated shortof=theforward endlof thezouter. conduit: IL and is provided with: an outer; halfcircleradial.fiange-33; welded or-otherwise suitably secured thereto. Just-forwardofthislfiange 331*the outenconduit I T is.- similarly provided. with an: inner half-circle: radial. flange 34;. Bolts 35 connect I the =two flanges 33. and 34- .to-thereby se.- cure; the; forward end: of. the. inner conduit, I6. within,- and inconcentric. relation: to, the.- outer conduit I I; It. also .will 'be :seen that the-flanges 33 andzfiltform-a closure-for-the-lower half 01 the forward-.endof the duct-2|. A member 38, shaped. generally-- like: half a a; funnel (Figure; 5).. and having longitudinal side-.flanges:31; formsan outwardly.fiaringiextensionof the lower half- 01 the-forward end of theinner conduit? 5.. The rearwardend of themember His-provided with an outer arcuate rib-38 which fits in a-corresponde ing 31131131767 groove-Sl-formedimthe inner sur: faces.-- of l the: flanges: 33; and-3:4; The; rib :38-1 thusprevents-longitudinal displacement of the. mam.- ber 35, whilethesideflanges-4O of'the adjustableextension :41" of. the upper halfoilthe. duct ZI bear upon the side flanges 31 ofthe.-member- 36.- to prevent upward displacement. thereof; It will thus be seen-thatruponremoval of the adjustable extension .4], the-member. 35 can belifted up and away to-ex-pose. the-.bolts 35 which can.then'be removed'fou detachment-of the inner conduit I6 from the entire nozzle assembly.

From the foregoing it. .will.be.seen that..the ob jects. off the. invention have. been. accomplished in a simple and inexpensive manner. It; alsois apparent that various structural changes. in the specific embodiment of "the invention shown anddescribed will beevident to one skilled in the art; Therefore, the invention embraces all modifications that come within the spirit and'scope-of the following claims.

' I claim:

1. A suction nozzlefor use'with'a pneumatic conveyorsystem to effect the discharge of finely divided bulk material from. a. container having a horizontally-disposed.bottom wall, said nozzle comprising: a. fixed: tubular: conduit.v adapted. to

be mounted in a horizontal position exteriorly of the containeria concentrically-arranged, extensible, double-wall tubular conduit telescopingly associated with said fixed conduit for projection into the container and axial movement along the bottom wall thereof, the inner wall of said extensible conduit forming a suction discharge passageway and the space between the walls of said extensible conduit forming a duct for conveying material-entraining air from outside the container for discharge adjacent the intake end of said passageway, said fixed conduit being received between the two walls of said extensible conduit; a non-metallic sleeve bearing mounted within and engaging the inner surface of the forward end of said'fixed conduit and embracing the outer surface of the inner wall of said extensible conduit; and non-metallic bearing blocks carried by a lower portion of said forward end of the fixed conduit and engaging the inner surface of the outer wall of said extensible conduit.

2. The structure defined in claim 1 in which the bearing blocks have projections thereon extending loosely through corresponding openings in the fixed conduit and into corresponding recesses in the sleeve bearing to retain said blocks and said bearing in place.

3. The structure defined in claim 1 in which both of the conduits are circular in transverse section and the outer surface of the sleeve hearing is shaped in axial section to make substan tially line contact with the inner surface of the fixed conduit.

4. The structure defined in claim 1 in which the sleeve bearing and the bearing blocks are of synthetic linear polyamide.

5. The structure defined in claim 1 including non-metallic bearing strips secured longitudinally within the fixed conduit beneath the inner wall of the extensible conduit for supporting engagement with said inner wall.

6. A suction nozzle for use with a pneumatic conveyor system to effect the discharge of finely divided bulk material from a container having a horizontally disposed bottom wall, said nozzle being adapted to project through an upstanding wall of the container for axial movement in a horizontal position along the bottom wall thereof, said nozzle comprising: inner and outer spaced concentric tubular conduits, one end of said inner conduit being adapted to be connected to the suction intake of a pneumatic conveyor system. the other end thereof forming a material intake opening, and the space between said conduits forming a duct for conveying material-entraining air from outside the container for discharge adjacent said intake opening, the lower portion of the forward end of said inner conduit terminating short of the forward end of the outer conduit; flange means detachably connecting the lower portion of the forward end of said inner conduit to said outer conduit and closing the lower portion of the forward end of said duct; means detachably secured in place by said flange means and engaging the forward end of the lower portion of said outer duct to form a forwardly flaring extension of the lower portion of the forward end of said inner duct; and detachable means overhanging said intake opening and defining an extension of the upper portion of said duct, said extension being closed at the forward end thereof and having air discharge openings in the opposite lower sides thereof.

'7. The nozzle structure defined in claim 1 in combination with a container having side walls which converge downwardly to form a troughshaped horizontal bottom, and a bearing strip for said nozzle composed of synthetic linear polyamide secured to said bottom for substantially the full length thereof.

. RAGNAR A. NORBOM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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