gusanos link belt.pdf

8/9/2019 GUSANOS LINK BELT.pdf

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Link-Belt Screw Conveyors

Innovative Technologies, Creative solutions

Material Handling Solutions


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Table of Contents

ntroduction 2

Description of Components 6

ComponentsClamps 90Conveyor Screws, Helicoid 50Conveyor Screws, Sectional 52Covers, Flared 87Covers, Hip Roof 88

Covers, Semi-Flanged and Flanged 86End Bearings 77End Flanges 91Flighting, Helicoid 51Flighting, Sectional 54

Hangers 62Ribbon Conveyor Screws and Flighting 56Seal Glands 81

Seals, Trough End 77Shafts, Coupling 59Shafts, Drive and End 58Slide Gates 92Split Flight Couplings 60Spout, Discharge 92Spout, inlet 94

Components (cont'd.)Shrouds 90Supporting Feet / Saddles 91Trough End Plates 71

Troughs, Double Flanged 84Troughs, Flanged and Angle Flanged 83Troughs, Flared 84

Troughs, Tubular 85

EngineeringCapacity Factors 36Component Groups - Class of Service 39

Component Group Selection 38Conveyor Designation System 49Conveyor Screw Deflection 44Horsepower Requirements 41Material Classification 25Selection of Conveyor Size and Speed 35Screw Feeders 46Torsional Ratings of Conveyor Screw Parts 43

Layout and DesignLayout Information 21Technical Data 20

©2003 by FMC Technologies, Inc.


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Link-Belt ® Conveyor Equipment

Sets the Standard for a Demanding IndustryFor 125 years, FMC Technologies and its predecessor Link-

Belt ® have designed and built conveyors and componentswhich have set the standard of excellence in the bulk material

handling industry.

FMC pioneered the development of bucket conveyors, screwconveyors and feeders, bucket elevators and related

conveyor components.

While your requirements are special to you, our engineersprobably have faced similar situations and are intimately

familiar with the challenges of handling bulk materials.

Our design engineering and production experience are thedifference which sets FMC Technologies' conveyor equipment

apart in reliability and dependability. We want to be ourcustomers' most valuable supplier. Put us to work for you.

FMC TECHNOLOGIES, MATERIAL

HANDLING SOLUTIONS OPERATIONFMC Technologies Material Handling Solutions Operation in

Tupelo, Mississippi, is one of the most modern conveyorequipment plants in the industry.

Our 330,000 square foot plant and office complex houses our

sophisticated computer-aided design group adjacent to thisvery modern manufacturing facility.

Administration, sales, engineering and manufacturing

interface daily in this excellent operating environment. Theresult is product quality and efficiency that result in both

performance and price advantages for you.

ABOUT OUR PRODUCTSBelt conveyor idlers, underground belt conveyors &

equipment, engineered screw conveyors, flighting augerand feeders and bucket elevators are the principal produmanufactured at our Tupelo location. In addition, we

produce Pull-Pak units, which is a line of compact ropecapstans used to move rail cars and marine barges.

All FMC Link-Belt conveyor products meet or exceed CE

standards, and all Link-Belt equipment is produced toconform with OSHA operational safety requirements.

CUSTOMER SERVICEPrompt shipment, on-time delivery and after-the-saleservice are FMC Technologies trademarks. Response to

your inquiries, sensitivity to your installation critical path,reliable delivery and follow-through have built our reputaas a service oriented company.

Our customer service specialists understand your needs

and are experienced in meeting them. In addition to thesubstantial inventory of Link-Belt equipment and

replacement parts at our Tupelo plant, you can look tohundreds of authorized stocking distributors located

throughout the United States (and Canada) to provide yoprompt local service.

LOOK TO LINK-BELT! COUNT ON US


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Greek mathematician and physicistArchimedes is acknowledged as thenventor of the screw conveyor in 235-240 B.C., and essentially his designhas not changed since then.

FMC and Link-Belt added the newand innovative applications whichmake the Archimedian screw thendispensable tool it is. Plus, FMC'sconveyor equipment specialistsmproved materials and fabricationechniques and added electricity as a

power source in the 125 years wenave specialized in manufacturingscrew and conveyor components.

To the basic Archimedian screw Link-Belt and FMC added conveyorsystems and screw feeders, designedhem for every conceivable application

and manufactured them so well wehave become the standard for thendustry.

Application engineering is a major

eason for the industry's wideacceptance of the Link-Belt screwconveyor. Studied attention to detailduring this phase eliminates costlynstallation and operation errors.

Close tolerance machining andabrication in our state-of-the-art

manufacturing facility assureequipment quality and performance.

Our ability to meet your needs with abroad selection of screw conveyorsand components is important to you,

plus your confidence that theequipment you purchase from FMC'sConveyor Equipment Division will earnts stripes and pay its own way, givingyou a good return on your investment.

Link-Belt ® Screw Conveyors and Screw FeedersQuality Bulk Handling Equipment that Pays Its Way


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Engineered for every type of service.

No one can match our ability to

give you the right equipment foryour application. FMC engineerspioneered the development of screwconveyors and components for thewidest range of materials, purposesand applications. Whether the jobinvolves light-duty service-conveyingegg powder, for example-or severeoperating conditions-like round-the-clock coal delivery to a power plant-wehave the in-depth knowledge andexperience to provide just whatyou need.

Link-Belt Screw Conveyors areruggedly built, accuratelymanufactured and performanceproven. And our unequalled fieldexperience is your assurance of thebest in service and recommendations.

Clean, compact design savesspace, simplifies installation.Link-Belt Screw Conveyors adaptreadily to tight quarters and congestedlocations. No matter how many twistsand turns your operation takes, thereis a Link-Belt space saving ScrewConveyor to fit. Our conveyors operateeffectively in horizontal, vertical orinclined positions. Their compactdesign permits easy installation. Andthey're simple to support.

If you should need replacement parts,you can count on controlled-tolerancestandardized parts that meet CEMAspecifications. They're interchangeablefor fast, easy assembly, and they don'trequire special tools.

So if space is at a premium, or ifyou want simple installation andmaintenance for better on-lineperformance, dependable Link-BeltScrew Conveyors are your best choice.

Top: Sugar is handled by twin screw feedersnd helicoid conveyors in this large bakery.

Drop-bottom troughs permit easy access and

uick cleaning of all parts.

Center: Screw conveyor augers are usedhroughout this combine for gathering,

conveying, elevating and distributing the harvest.

Bottom Left: Heavy-duty sectional flight conveyor

augers installed on boring machine.

Bottom Right: Totally enclosed screw conveyorscan assure a clean, safe operation.


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When you buy from FMC, you can rely

on our factory-stocked equipment andparts inventories which are

complemented by more than 140 NorthAmerican distributors with over 400

branches. So you're guaranteed atimely response to your parts and

service needs. You keep downtime to aminimum because you get fastturnaround-from order entry to parts

delivery at your plant or jobsite.

When it comes to bulk materialhandling, come to FMC.

FMC has the uncommon ability to solveany screw conveying problem you might

face. We've got the equipmentselection, the fund of experience and

the kind of service you need to speedyour material handling operation andsave you money.

Top Left - Totally enclosed screw conveyors,compact in design, are located in many foodprocessing plants

Top Right - Over 40 feet of screw conveyorscarry malt and rice from storage to mills inthis factory.

Center Left - Typical installation providesclose fitting gates and connections,

Center Right - Helicoid screw conveyordelivers 50 tons of coal per hour to boilerroom bunkers.

Bottom - Granular shell lime distributionsystem at a large chemical facility.

Nearby service when you need it.


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Component Description

Screw conveyors are one of the oldestand simplest methods for moving bulk

materials and consist primarily of aconveyor screw rotating in a stationaryrough, Material placed in the trough is

moved along its length by rotation of thescrew which is supported by hangerbearings. Inlets, outlets, gates and otheraccessories control the material and itsdisposition.

Screw conveyors are compact, easilyadapted to congested locations and canbe mounted horizontal, vertical, and innclined configurations. Their supportsare simple and easily installed.

These versatile conveyors can be usedo control the flow of material in pro-

processing operations which dependupon accurate batching . . . or as a

mixer, agitator or stirrer to mix andblend dry or fluid ingredients, providecrystallization or coagulant action, ormaintain solutions in suspension,

Screw conveyors can be effectivelysealed to prevent dust or fumes fromescaping or dirt or moisture fromentering. They can be jacketed toserve as a dryer or cooler, orfurnished in a wide variety of materialsto resist corrosion, abrasion or heat.

Screw conveyors are used as earthaugers to dig post holes or to boreunder highways for installation ofculverts. They are also used

extensively on combines, threshingmachines, hay bailers, fodder blowers

and many other farm machines.

Screw feeders are modified screwconveyors used to control the flow ofmaterial at a constant or variable ratefrom track hoppers, storage hoppers,bins or tanks. They are suitable forhandling a wide variety of materialsranging from fines to a combination offines and lumps. Under many conditionsfeeders are also used as a valve.

Screw feeders are totally enclosed,compact, simple in design and dust-tigh

They are economical to install, operateand maintain.

Conveyor ScrewThe conveyor screw is the rotatingportion of a screw conveyor whichmparts smooth and positive motion tohe bulk material being conveyed. It

consists of spiral flighting mounted on

a pipe and is made either right or lefthand to suit the screw rotation and thedesired direction of material travel.

Conveyor Screw with DriveShaftThe conveyor drive shaft connectsthe conveyor screw to the driving unitand transmits rotary motion to the

screw. Coupling bolts secure the driveshaft in the conveyor screw.

Conveyor Screw with DriveShaft, End Shaft and CouplingThe conveyor drive shaft, end shaftand coupling support the conveyorscrew sections and keep them inalignment. The end shaft is located athe end opposite the drive shaft.

Couplings are used to connectsuccessive conveyor screw sections

when more than one section isnecessary to make up the total lengthof conveyor. The shafts and couplingare secured in the conveyor screwsby coupling bolts.


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component description

Trough Ends and Hangers

The trough ends support theconveyor drive and end shafts while

the hangers support the conveyorcouplings, thereby maintaining properalignment and clearance between theconveyor screw and trough.

To provide additional protection forthe drive shaft and end shaft

bearings, for or against the materialbeing handled, trough end seals are

assembled between the flangedblocks and the trough end plates.

Conveyor Trough with Inlet

Opening and Discharge SpoutThe trough is the enclosure in whichthe material is confined and guided in itsmovement. Trough end flanges preservethe contour of the trough, facilitateassembly of adjoining sections, andinsure accurate alignment. Supportingfeet at the trough joints or saddleslocated between the joints, support theintermediate trough sections.

Discharge spouts provide outlets for thematerial and direct its flow to bins

or succeeding equipment- With more

than one discharge point in a conveyor,selective control may be exercised bymeans of slide gates, made integralwith the discharge spouts.

Trough covers with fasteners completethe conveyor enclosure. Material is fedinto the conveyor through inlet openingsin the cover.

Typical Screw ConveyorComplete With Drive

A shaft mounted speed reducermakes a simple and compact drivecombination. The drive consists of astandard shaft-mounted speed reducerwith adapter having a built-in, seal andmounted on a steel plate trough end. Awelded steel adjustable motor supportbracket is rigidly mounted on theadapter and provides ample clearanceover the trough end for easy trough

cover removal.


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Helicoid Flight Conveyor ScrewsThe helicold flight conveyor screw ismade of a helix, formed from a flat steelbar or coil strip and mounted on a pipe

or shaft. The helix, formed by specialolling equipment to the required

diameter, pitch and thickness, is asmooth, continuous one-piece flight.

By virtue of its one-piece construction,t possesses superior strength. Theabsence of laps, rivets or welds onhe carrying face of the Flight

promotes and maintains cleanlinessand reduces wear. The rolling processeffects a hardening and smoothing ofhe flight surface which increasesesistance to wear and reducesriction and power consumption.

The flight is fastened to the pipe, orshaft, by intermittent or continuouswelds and with or without formed steelend lugs. The pipe, of a size carefullyselected for adequate torsional strengthand resistance to excessive deflection,has internal collars at each end. Thesecollars are permanently inserted andhave appropriate inside diameters toaccept coupling or end shafts.

The assembled helicoid flight conveyorscrew is solidly constructed andexceptionally sturdy, and its inherentbalance permits operation at highspeeds. Its distinctive characteristicscontribute to maximum efficiency,durability and economy.

Helicold flight conveyor screws arenterchangeable with sectional flightconveyor screws of the same diameterand shaft size.

Helicold flighting is made with regular

pitch approximately equal to thediameter. It can also be furnished withother than regular pitch and in a wideange of diameters, thicknesses andengths to meet the most exactingequirements.

For extremely heavy duty the flightingmay be continuously welded to the pipeor shaft on one or both sides.

Consult FMC for information on specialequirements.

Sectional Flight Conveyor ScrewsSectional flight conveyor screws aremade of individual flights, eachblanked from a flat steel plate andformed into a helix. The flights arebutt welded together and fastened tothe pipe or shaft by intermittentor continuous welds and with or withoutformed steel end lugs. Sectionalflights are formed with regular pitchapproximately equal to the diameter.

Sectional flight conveyor screws areinterchangeable with helicoid flight

conveyor screws of the same diameterand shaft size.

Sectional flights afford flexibility inchoice of diameters, pitches and

thicknesses. The sectional flightconveyor screw is a sturdilyconstructed assembly, carefullydesigned to render efficient,economical and lasting service.

When desired, sectional flights maybe lap welded together, or flights maybe continuously welded to the pipe onone or both sides, thus providingexceptionally rugged construction forthe most severe conveyingapplications.

Many variations of sectional flightconveyor screws can be furnished tomeet specific needs. Some of theseare listed on the following pages.

Quik-Link Conveyor ScrewsThe Quik-Link conveyor screw Isdesigned for easy removal from theconveyor trough. Each section ofscrew is provided with a Quik-Link keylocated at one end of the pipe. Byremoving this key, a conveyor screw

section and coupling with hanger can bquickly and conveniently disassembledwithout disturbing other components.Quik-Link conveyor screws are availabin both the helicold flight and sectionalflight construction.

Conveyor Screws

Helicoid flight conveyor screw

Sectional flight conveyor screw


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Cut flight conveyor screws have notches cut inthe periphery of either helicoid or sectional flights.These notches supplement the conveying actionwith a moderate mixing action. They are used for

light, fine, granular or flaky materials.

Ribbon flight conveyor screws consist ofcontinuous helical flighting formed from steel barand secured to the pipe by supporting lugs. Theyare used for conveying sticky, gummy or viscoussubstances, or where the material tends to stick toflighting at the pipe.

Conveyor screws with paddles have paddlesspaced at intervals and set to partially oppose theforward flow, to provide a moderate mixing or

stirring of materials being conveyed. Paddles areadjustable and may be set at any angle toproduce the desired degree of agitation. They areused for light or medium weight, fine, granular orflaky materials.

Cut and folded flight conveyor screws providefolded segments which act as lifting vanes toproduce a cascading effect. This promotesagitation and aeration, resulting in better mixing.They are used for light or medium weight, fine,granular or flaky materials.

Short pitch conveyor screws are of regularconstruction except that the pitch of the flights isreduced. They are recommended for use ininclined conveyors of 20 degrees slope and over,including vertical conveyors and are extensivelyuse as feeder screws. They retard flushing ofmaterials of a fluid nature.

Cut flight conveyor screws with paddles havepaddles mounted at intervals and set to counteractthe flow of materials, considerably increasesthe agitation and mixing action produced by thecut flights.

Paddle conveyor screws have formed steelblades mounted on rod shanks inserted throughthe pipe. Conveying action can be controlledby adjusting the angle of the paddles. Theyare used for mixing, blending or stirring dry orfluid materials.


Conveyor Screws


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Tapering flight conveyor screwsare frequently used as feeder screwsfor handling friable lumpy material

from bins or hoppers and also to drawthe material uniformly from the entirelength of the feed opening.

Stepped diameter conveyor screwsconsist of flights of different diameters,each with its regular pitch, mounted intandem on one pipe or shaft. They arefrequently used as feeder screws, withthe smaller diameter located underbins or hoppers to regulate the flowof material.

Stepped pitch conveyor screwsare screws with succeeding single orgroups of sectional flights increasingin pitch and are used as feederscrews to draw fine free-fIowingmaterials uniformly from the entirelength of the feed opening.

Long pitch conveyor screwsare occasionally used as agitatorsfor liquids or rapid conveying of veryfree-flowing materials.

Double fIight conveyor screwsof regular pitch promote a smoothgentle flow and discharge of certainmaterials.

Double flight short pitch conveyorscrews assure more accurateregulation of feed and flow in screwfeeders and effectively deter flushingaction of fluid materials.


Conveyor Screws


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Conveyor Screws

Ribbon Flight Conveyor Screwsconsist of sectional flights, butt weldedtogether to form a continuous helix.

Flights are secured to the pipe bysupporting lugs.

Variations of diameter, pitch, flightwidth or thickness can be furnished.Also, these screws can be furnishedwith either continuous or sectionalflights, lap or butt welded together

Ribbon flight conveyor screws are thesolution to most conveying problemsencountered in the handling of sticky,gummy or viscous materials. Thetendency of materials of this nature toadhere and build up at the juncture ofsolid flight with the pipe is overcomeby the open construction of the ribbonflight. Raw sugar, molasses, asphalt,hot tar, sticky feed mixes, and similarproducts are typical of the manymaterials successfully handled byribbon flight conveyor screws.

Providing the periphery of ribbonflights with a beveled edge improvesoperation and reduces powerconsumption when handling materialswhich tend to pack or trowel betweenflights and trough. Consequently,beveled edge ribbon flight conveyorscrews are usually subjected toextremely heavy loads, andconstruction is accordingly heavy andrugged. The ribbon flights aresupported on the pipe or shaft bysteel lugs, generously proportioned toresist bending.

Where the material handled movesvirtually en masse, there is but veryslight difference in capacity between

ribbon and solid flight conveyorscrews of the same size. Mixingaction without supplementary meansof agitation is negligible.

Ribbon Flight Conveyor Screwwith PaddlesTo provide moderate mixing or stirringof materials being conveyed, paddlescan be furnished, spaced at intervalsand set to partially oppose the forwardflow. Paddles are adjustable and maybe set at any angle to produce thedesired degree of agitation. They areused for light or medium weight, fine,granular or flaky materials.

Multiple Ribbon Flight ConveyorScrewsThis type of screw consists of two ormore ribbon flights of differentdiameters and opposite hand,mounted one with in the other on thesame pipe or shaft by rigid supportinglugs. Material is moved forward byone flight and backward by the other,thereby including positive andthorough mixing.

Abrasion-Resistant ConveyorScrewsThe particularly severe serviceencountered when conveying abrasivematerials has prompted manyattempts to overcome excessive wearon flights. Several successful methodshave been developed.

Each of these methods offers specificadvantages depending on the natureof the material handled and theapplication. For a careful analysis andrecommendation, consult FMCConveyor Equipment Division.

Hard surfacing by application of aspecial compound, by arc or torch,the flight periphery or face, or bothprovides an exceptionally hard surat the points of greatest wear.

For severe applications, conveyorswith high alumina ceramic tile bondto the flight periphery or face are aavailable.

Corrosion-Resistant Conveyo

ScrewsCorrosion is manifested in so mandifferent ways that no one choice omaterial will suit all requirements. Twithstand the effects of corrosionencountered in many fields of induconveyor screws are fabricated ofstainless steel, Monel metal,aluminum, and other materials.

Galvanizing and other coatingmethods have proved effective undmildly corrosive conditions. Vulcanor bonded rubber covering of theentire conveyor is frequentlysatisfactory for resistance to extremcorrosive action.

Heat-Resistant ConveyorScrewsConveyor screws for high temperaapplications are made of many of tavailable heat-resistant alloys. Sevof the stainless steels and other hichrome alloys are particularly suitafor this service.

Ribbon flight conveyor screw

Ribbon flight conveyor screw with paddles


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Drive Shafts, End Shafts and Couplings

Conveyor drive shaft

Conveyor end shaft

Conveyor coupling

Quik-Link conveyor screw

Split flight coupling

The conveyor drive shaft delivers thedriving power, and is therefore carefullydesigned of quality steel of the propercharacteristics to provide adequateorque, bending and shear strength, and

with closely controlled tolerances forcorrect bearing clearances.

For conveyors of unusual length or forseverely heavy loads, alloy steels,heat-treated high carbon steels or3-bolt connections, are used.

ig-drilled coupling bolt holes andaccurately cut keyways contribute toease of assembly.

The conveyor end shaft supports theast section of conveyor screw and isurnished with close tolerances for

proper operation in end bearing.Coupling bolt holes are jig drilled fornterchangeability and ease of assembly.

Conveyor couplings connect andspace adjoining sections of conveyorscrew and transmit rotation.

Carefully selected steels, with accurateheat-treating or hard surfacing whenequired, insure ample strength andesistance to wear for the kind of service

specified.

For conveyors of unusual length or forseverely heavy loads, alloy steels, heat-reated high carbon steels or 3-bolt

connections are used.

Close tolerances on diameters andg-drilled coupling bolt holes assurenterchangeability and ease of assembly.

Quik-Link conveyor screws provide aneasy means for the quick removal of aconveyor screw section and couplingwith hanger without disturbing othercomponents. Regular couplings areused with these screws.

Split flight couplings permit installingor removing individual conveyorscrews without disturbing adjoiningsections. With split flight couplingsnstalled on both sides of eachhanger, conveyor screws can beemoved without disturbing the

hangers. The Link-Belt split flightcoupling is sturdily constructed andg-dri lled for coupling bolts.


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HangersNo. 216 hangers have formed steel box frames of superiorstrength and rigidity and are excellent for heavy service. Theare mounted with in the conveyor trough. Mounting holes areslotted parallel with the conveyor to permit adjustment andalignment. These hangers are normally furnished with hard i

babbitted, bronze, oil impregnated wood or molded fabricbearings, but can also be furnished with special bearings.

No. 216F hangers are similar in construction to No. 216hangers except they are designed to mount in, flared trough

No. 220 hangers are similar in construction to No. 226hangers, except they are mounted on top of the trough flangMounting holes are slotted parallel with the conveyor to provadjustment and alignment. These hangers are normallyfurnished with hard iron, babbitted, bronze, oil impregnatedwood or molded fabric bearings, but can also be furnished wspecial bearings.

No. 226 hangers have a rigid, formed-steel box frame withclearance for passage of material in large volume. They aremounted within the conveyor trough. Mounting holes are sloparallel with the conveyor to permit adjustment and alignmenThese hangers are normally furnished with hard iron, babbittbronze, oil impregnated wood or molded fabric bearings, butcan also be furnished with special bearings.

No. 270 ball bearing hangers have self-aligning ball bearinThe frame is a box-member top-bar with a pipe stem supporthe bearing. The bearing is factory adjusted for the properlength from the top-bar and locked with a sealant and a locknut. The frame is designed for mounting inside the trough anslotted mounting holes parallel to the conveyor permitadjustment and alignment.

No. 316 hangers have formed steel frames of superior strenand rigidity and are excellent for heavy service. They aremounted within the conveyor trough, are self-adjusting and waccommodate operating variations which may exist between

conveyor screw and trough. Mounting holes are slotted parawith the conveyor to permit adjustment and alignment. Theshangers are normally furnished with hard iron, babbitted,bronze, oil impregnated wood or molded fabric bearings, butcan also be furnished with special bearings.

No. 326 hangers have a rigid, formed steel frame withclearance for passage of material in large volume. They aremounted within the conveyor trough, are self-adjusting and waccommodate operating variations which may exist betweenconveyor screw and the trough. Mounting holes are slottedparallel with the conveyor to permit adjustment and alignmenThese hangers are normally furnished with hard iron, babbittbronze, oil impregnated wood or molded fabric bearings, but

can also be furnished with special bearings.

No. 216 hangers

No. 216Fhangers

No. 220 hangers

No. 226 hangers

No. 270 ballbearing hangers

No. 316 hangers

No. 326 hangers


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Trough End Plates

Trough end with feetTrough end without feet

Tubular trough end Flared trough end

Trough end with doubleroller bearing

Trough end plates for either U-trough or flared troughare made of heavy gauge steel plate with the toplanged to support the trough cover. They are furnished

with or without supporting feet.

Trough end plates can be made of stainless steel ornonferrous metals for corrosive or high temperatureapplications. They can also be furnished withprotective coatings, such as galvanizing.

They may be equipped with either sleeve, bolt, or rollerbearing flange blocks, or with the addition of amounting shelf, pillow block bearings.

Drive Shaft Trough Ends are of the double ballbearing and double roller bearing types. Each consistsof a rigid shaft, operating in double bearings anddesigned to accommodate both radial and thrust loads.The radial or overhung load is usually a chain driveconnected to a power source. Since the bearings willalso accept thrust loads in either direction, the need forauxiliary thrusts is eliminated.

Drive shaft trough ends with double ball bearingsconsist of double ball bearing flanged blocks rigidlyattached to heavy steel plate trough ends for either U-roughs or flared troughs. The gray iron housings are

of one-piece construction and are precision machined

or accurate alignment. Effective seals are provided inhe flanged blocks to exclude dirt and moisture andetain lubricant.

Drive shaft trough ends with double roller bearingsconsist of heavy duty double roller bearing flangedblocks mounted by means of machined surfaces intoextra heavy steel plate trough ends for either U-troughsor flared troughs. The gray iron housings areaccurately machined and fitted with roller bearings ofhigh radial and thrust capacity. The blocks haveeffective seals and are arranged for easy lubrication.

Countershaft trough ends are used on screw

conveyors where application of right angle drives isnecessary due to space limitations, interference ofadjoining equipment or for better service andmaintenance accessibility.

Application of countershaft trough ends permits drivenstallations alongside, above or below the conveyorand permits using horizontal drives for inclinedconveyors. A common drive for two conveyorsntersecting at right angles, or a battery of parallelconveyors driven from a common source, can beeadily arranged


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Seal Glands, Trough End Seals andTrough End Bearings

Seal glands and trough end sealsare used to provide additional bearingprotection against dust or fumes from withinthe trough and prevent entrance, along theshaft, of dirt, moisture or lubricant.

The trough end seal housings are madeof gray iron and are designed forassembly between babbitted, bronze or

ball bearing flanged blocks and thetrough end plates. They can be providedwith lip-type seals for effective protectionfor or against the materials beinghandled, with felt seals when handlingdusty materials, or with waste packingwhen handling abrasive materials.

Seal glands consist of gray iron, splitflanges into which packing materials arecompressed against machined steelcollars. They are used internally on alltrough ends except the outboard bearingtype on which they are externallymounted. These seals provide maximumprotection for or against the materialsbeing handled.

Trough end bearings

Babbitted and bronze bearing flangedblocks are made with one-piece gray ironhousings. Babbitted bearing blocks are forgeneral use where loads and speeds aremoderate. Bronze bearing blocks are usedwhere heavy bearing pressures, impactloads or temperature conditions areinvolved.

Ball bearing flanged blocks consist ofsingle row, deep groove, self-aligning ballbearings, which are effectively sealed,mounted in one-piece gray iron housings.Spring locking collars with two set screwshold the bearings firmly on the shafts.

Trough end seal

Internal mountingseal gland

Ball bearing

Flanged block


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Troughs

The trough not only confines and guides the flowof material, but also serves as the housing inwhich all operating components are supportedand held together in their proper functionalelationship. Accuracy in manufacturing andnherent strength to maintain this accuracy are

herefore, essential.

Link-Belt designs, and manufacturing methods,are constantly being improved to provide thesequalities to the fullest extent while at the sameime affecting economies in weight and spaceequirements.

Flanged trough - By forming the top flangesntegrally with the trough sides from a single steelsheet, adequate strength and rigidity is obtained

without superfluous bulk or weight. Steelconnecting flanges, securely welded at each endn special welding fixtures to assure square, trueends, facilitate assembly, insure proper alignmentand preserve the contour of the trough.

Angle Flanged trough - This trough is identicaln construction to the flanged trough, except thatop flanges are obtained by securely welding

structural steel angles to the trough.

Flared trough - This trough is of conventionalconstruction except that trough sides are flaredoutward to afford a wider top opening. Thisesults in improved feed and conveying action

with sticky materials or materials which are notentirely free flowing. It is customarily used withibbon flight conveyor screws.

Corrosive or high temperature applications mayrequire the specific qualities that make stainlesssteel and non-ferrous metals well adapted to theseservices. In general, any type of trough that can befabricated of mild steel can also be made ofstainless steel or aluminum, brass, bronze, copper,

Monel metal, nickel, etc. For resistance to corrosionthere are numerous protective coatings that are

applied to steel troughs and covers. Galvanizing,tinning, chrome plating, etc., are all effective forcertain applications. Vulcanized or bonded rubbercoatings resist abrasion and corrosion.

Flanged trough

Angle flanged trough

Flared trough


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Troughs

Drop bottom troughs are equipped with a dropbottom usually hinged, held in place by springclamps of various types for ready access totrough interior, conveyor screws and hangers.

This design facilitates quick, thorough, andfrequent cleaning of the trough, screw and otherparts and is particularly useful to combatinfestation and promote sanitation.

Channel side troughs are made with separatedetachable trough bottoms, bolted or clamped to

formed or rolled steel channels. The channelsmay be of any reasonable length to span widelyspaced supports. Trough bottoms are made inlengths up to 12 feet.

This trough is occasionally selected for ease ofreplacement of trough bottoms subject tounusually severe abrasive or corrosive wear.

Trough Support

Supporting feet are of formed steel for use withend flanges and provide a convenient means ofaligning and supporting conveyors from floors,and supporting structures.

Supporting saddles are used when location ofsupport points does not coincide with the spacingof joint flanges or when troughs with butt strappedconnections are used.

Support saddle

Support feet

Channel side trough

Drop bottom trough


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Trough Covers

Covers are used for protection of operatingpersonnel, dust control or protection for oragainst the material being handled. Whenequired, protective seals can be furnished.

Plain covers consist of flat steel sheetsand can be furnished with spring clamps,

screw clamps or bolts.

Semiflanged covers are flanged 30degrees along the sides and provided with

spring clamps attached to the top side ofhe cover These covers can also beurnished with screw clamps or bolts.

Flanged covers have right angle flangesalong the sides to provide a stiffer cover formore convenient handling. They arenormally attached to the trough with screwclamps or bolts.

Hip Roof covers are peaked to form a

ongitudinal ridge. They are normallyurnished for use in outdoor applications

because of their ability to shed water.

Shrouds are used in U-trough sections ofscrew feeders to decrease the clearancebetween the cover and feeder screw toobtain proper feed regulation.

between the covers and troughs. Covers aremade in three general types: plain, semi-flangedand flanged.

Plain Cover

Semiflanged Cover

Flanged Cover

Shroud


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Trough Discharge Spouts and Gates

Discharge spouts and gates afford the means fordischarging material from the trough and for

connection to succeeding equipment to which materialis delivered. Gates provide for selective control ofmultiple spouts.

All spouts and gates are of welded steel constructionwith connecting flanges punched with accuratelyspaced holes for interchangeability and ease ofassembly.

Spouts and gates can be fabricated of stainless steeland nonferrous metals. Spouts of special design can

be furnished to accommodate unusual conditions.

Plain discharge openings are cut in the bottom of thetrough at the desired location to provide freedischarge of material. They are used for delivering toopen or closed storage or similar applications.

Discharge Spouts are welded in place whenfurnished with a complete conveyor. They arefurnished in thicknesses proportioned for the size andthickness of trough.

Flush end discharge spouts are furnished welded inplace on flanged or angle flanged trough. They arefurnished in thicknesses proportioned for the size andthickness of the trough.

Hand Slide Gates are made to attach to dischargespouts and can be operated from any one of the foursides, provided there is sufficient clearance for thegate in its open position.

Rack and Pinion slide gates have cut tooth rackswelded to the side-plates and actuated by cut toothpinions mounted on pinion shafts operated by hand

wheels or chain wheels. These are available witheither flat slide plates or curved slide plates.

Air Operated gates are high quality units designed forlow-friction performance in applications requiringfrequent gate operation. These gates are built toaccept a flange-faced air cylinder and have a rollermounted slide plate operating in a formed steelhousing. The cylinder can be furnished with the gateor supplied by the user for field installation. No airpiping or controls are provided with these gates.

Slide gates, either hand or rack and pinion operatemay be installed in practically all applications for

operation either parallel or at right angles to takeconveyor axis. Rack and pinion operated gates mabe furnished with chain wheels and chains for remocontrol. Pinion shafts may be extended toaccommodate various operating arrangements.

Plain discharge

opening

Discharge Spout

Flush end discharge

spout

Rack and pinion

curved slide gate

Rack and pinion

flat slide gate


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Technical Data

The Link-Belt screw conveyor layout,engineering and component selectionnformation in this section is provided to

assist you in the selection of the properconveyor components for your particularmaterial handling requirement. It hasbeen compiled during the many years ofexperience designing numerous andvaried screw conveyor installations, andncludes detailed information on all Link-Belt standard screw conveyorcomponents and accessories.

The data and formulas presented permiteasy selection of the necessarycomponents for handling materialsunder normal operating conditions by

horizontal screw conveyors and screweeders.

Where unusual applications or severeoperating conditions are a factor orwhere there is doubt concerning thecorrect selection, contact FMC ConveyorEquipment Division, Tupelo, MS toassist you with additional information.

For prompt delivery, many of thesecomponents are carried in inventory atour authorized FMC Stocking Distributorocations and at our manufacturing

acility in Tupelo, Mississippi.

Portions of Engineering and ComponentSelection sections are reproduced fromConveyor Equipment ManufacturersAssociation CEMA books 300 and 350.CEMA Book 350 contains comprehen-sive screw conveyor reference material.Book 300 contains screw conveyordimensional standards.

CAUTION: Link-Belt ScrewConveyors and components must beinstalled, operated and maintained inaccordance with accompanying FMCService Instructions. Failure to followthese instructions can result inserious personal injury, propertydamage or both.

FMC Service Instructions accompanythe shipment of equipment. If additionalcopies of Service Instructions arerequired, they are available free ofcharge from FMC Corporation,Conveyor Equipment Division,Box 1370, Tupelo, Mississippi 38802.


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ayout information

Screw ConveyorsScrew conveyors are made with

either helicoid or sectionallighting of various thicknesses

n a wide range of sizes in bothight-hand and left-hand

assemblies. The conveyorscrews and troughs are made

in regular lengths, but can alsobe furnished in odd lengths tosuit requirements.


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layout information

Hangers - Hangers are locatedbetween conveyor screw sections. No.216, 220, 226, 270, 316 and 326hangers are located at trough joints inFigure B, page 22. All hangers shouldclear inlet and discharge openings.

Trough ends - The drive shaft or endshaft, depending on the direction ofmaterial travel, should have a thrustbearing to maintain clearancebetween the conveyor screws andhangers, and the conveyor screwsand trough ends. This preventsexcessive wear of operating parts andreduces power consumption. Thepreferred location for the thrustbearing is at the end of the conveyor,because the conveyor pipes andcouplings will then be in tensionduring operation.

Drive shaft trough ends of either thedouble ball bearing or double rollerbearing type will accommodate radialloads and thrust loads in eitherdirection. The radial or overhung loadusually consists of a shaft-mountedspeed reducer drive or a chain driveconnected to a power source.

Plain trough ends require auxiliary end

thrust provision. Depending upon thedirection of the thrust, either the driveor end shaft should have a bronzethrust bearing.

Seals - Trough end seals are used foradditional protection for or against thematerial being handled, or to protect

and preserve the trough endbearings and shafts when handlingabrasive or corrosive materials.

Troughs - Regular and half lengthtroughs, listed in Table 1, page 22,should be used to obtain therequired total trough length.Whenever possible, supporting feetshould be used at the trough joints,otherwise, use saddles as needed.Supporting feet located at the endsof the conveyor will allow removal ofthe trough ends without disturbingtrough alignment.

Covers - Covers are made with joints located at the hangers.Protective seals between the troughsand covers are easily applied whenNo. 216, 226, 270, 316, and 326hangers are used. Inlet openings inthe covers should clear hangers.

Drives - Drives should preferably belocated at the discharge end of theconveyor in order to keep theconveyor screws and couplings intension.

Assembly Bolts - Table 2 providesa guide to the quantities and sizes of

bolts required to assemble a screwconveyor. Bolts are listed for eachtype of hanger, for each shroud, foreach trough joint or trough end, andfor 10 foot and 12 foot long sectionsof bolted cover.

Assembly bolts for No. 316 and No.326 hangers are furnished withhanger assemblies.

Screw ConveyorsMany bulk materials are handled

easily and efficiently in screwconveyors. However, to insure thebest possible selection ofcomponents, it is recommended thatconsideration be given to the physicchemical and handling characteristicof all materials.

The essential characteristics includesize, flowability and abrasiveness ofthe materials. Other characteristics,such as contamination, corrosivenesdegradability, fluffiness, etc., mayinfluence the handling and should begiven consideration. Considerationshould also be given to materialswhich may assume differentcharacteristics under certainconditions of processing, atmospherage or storage. Many of the morecommon materials are classified in tMaterial Characteristics Table 4,pages 26 thru 34, and are given as aguide in selecting the propercomponents. Materials not appearinin the list can be classified bycomparison with similar materials orby establishing a classification usingthe Material Classification Code ChaTable 3, page 25.

The delivery of material to a screwconveyor must be at a controlled andfairly uniform rate.

(1) Four bolts(2) Six bolts(3) Eight bolts

(4) Ten bolts(5) Twelve bolts(6) Fourteen bolts

(7) Sixteen bolts(8) Eighteen bolts(9) Twenty bolts

(10) Eight bolts for U-Trough & ten bolts for Flared Trough


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layout information

Special applicationsOccasionally the characteristics of thematerial being handled are such thatother than conventional or regularequipment is required for the purpose,such as:

1. When the materials are extremelyhot, the screws and troughs maybe made of high temperaturealloy metals.

2. If the materials are sticky or viscous,ribbon flight conveyor screws may bethe choice. Furthermore, specialcoatings applied to the screws andtroughs may also aid the flow ofthe material.

3. Extremely abrasive materials mayrequire screws and troughs made ofabrasion resistant metals or thescrews may be provided with hardsurfaced flights.

4. When the materials are corrosive, it

may be desirable to make theconveyor screws and troughs ofstainless steel, Monel metal, nickel,aluminum, etc.

5. If the materials are to be mixed oraerated, a conveyor screw of ribbonflights or cut flights, or one of thesecombined with paddles may be usedto obtain the desired results.

6. Materials which are to be heated orcooled may require jacketed troughsarranged for circulating heating or

cooling media.

7. Contaminable materials may requireself-lubricated bearings and screwand trough construction which willeliminate pockets, cracks, etc. Suchscrews and troughs will prevent theaccumulation of the material andfacilitate easy cleaning.

How to select a horizontalscrew conveyorConsider the following factors whenselecting a horizontal screw conveyor:

Kind and character of material beinghandled, such as: size, flowability,abrasiveness, etc.

Weight of material in pounds percubic foot.

Maximum rate at which material ishandled in cubic feet per hour.

Maximum size of lumps in inches,average size of material and percentageof lumps in total volume.

Length of conveyor in feet.


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material classification

Preface to Material Table

The Material Characteristics Table 4 listsa wide range of bulk materials that canbe handled in screw conveyors. Thetable shows the first column the rangeof density that can be experienced inhandling that material. The "asconveyed" density is not specificallyshown but is often assumed to be at ornear the minimum.

The next column shows the material

code number. This consists of theaverage density, the usual sizedesignation, the flowability number, theabrasive number followed by thosematerial characteristics which aretermed conveyability hazards.

The component series column refers toselection of conveyor components asused in Tables 9, 10, 11, & 12 on pages39 and 40.

A very fine 100 mesh material with anaverage density of 50 lbs. per cubic footthat has average flowability and ismoderately abrasive would have amaterial code 50A10036. If this materialwas very dusty and mildly corrosive thenumber would be 50 A10036LT.

The Material Factor is used in thehorsepower formula to determine thehorsepower to operate a horizontalscrew conveyor. The calculation ofhorsepower is described on page 41.

The Material Characteristics Table is aguide only. The material code, and thematerial factor Fm are based onexperience. A specific material samplemay have properties that vary fromthose shown in the table. The range ofdensities will also vary depending onmoisture content as well as its source.


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engineering information

Lump Size LimitationsThe size of a screw conveyor not onlydepends on the capacity required, butalso on the size and proportion ofumps in the material to be handled.The size of a lump is the maximumdimension it has. A closer definition ofhe lump size would be the diameter

of a ring thru which the lump wouldpass. However, if a lump has onedimension much longer than its

ransverse cross-section, the longdimension or length would determinehe lump size.

The character of the lump also Isnvolved, Some materials have hardumps that won't break up in transithrough a screw conveyor. In that caseprovision must be made to handlehese lumps. Other materials may haveumps that are fairly hard, butdegradable in transit through the screwconveyor, thus really reducing the lumpsize to be handled. Still other materials

have lumps that are easily broken in ascrew conveyor and lumps of thesematerials impose no limitations.

Three classes of lump sizes applyas follows:

Class 1A mixture of lumpsand fines in whichnot more than 10% are lumps rangingrom maximum size to one half of the

maximum; and 90% are lumps smallerhan one half of the maximum size.

Class 2

A mixture of lumps and fines in whichnot more than 25%, are lumpsranging from the maximum size toone half of the maximum; and 75%are lumps smaller than one half ofthe maximum size.

Class 3A mixture of lumps only in which 95%or more are lumps ranging frommaximum size to one half of the

maximum size; and 5% or less arelumps less than one tenth of themaximum size.

Table 7, page 37 shows therecommended maximum lump size foreach customary screw diameter andthe three lump classes. The ratio, R,is included to show the average factorused for the normal screw diameterswhich then may be used as a guidefor special screw sizes andconstructions.For example:

Radial Clearance, inchesRatio, R =Lump Size, inches

This ratio applies to such unusual casesas screws 16 inches diameter mountedon 2 inch solid shafts; or 12 inchdiameter screws mounted on 6 inchdiameter pipes (the large pipe serving toreduce deflection of the screw).

The allowable size of a lump in ascrew conveyor Is a function ofthe radial clearance between theoutside diameter of the centralpipe and the radius of the insideof the screw trough, as well asthe proportion of lumps in themix. The following illustrationillustrates this relationship.


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To illustrate the choice of screw size

from Table 7, say the material is ice withMaterial Characteristic code numberD15, 35 to 45 lbs. per cubic foot andwith size distribution as follows:

4"x2," 9%2"x1," 41%1"x3 / 8," 22%minus 3 / 8," 28%.

This lump size distribution falls under

Class 1. From Table 7, the ratio R is1.75 and the radial clearance (4)(1.75) or 7 inches. This calls for an18 inch diameter screw.

Component Groups

To facilitate the selection of properspecifications for a screw conveyorfor a particular duty, screw conveyorsare broken down into threeComponent Groups. These groupsrelate both to the MaterialClassification Code and also toscrew, pipe size, type of bearingsand trough thickness.

If the material to be conveyed is notlisted in Table 4, pages 26 thru 34,then its Classification code may bedetermined from Table 3, page 25.

Table 8 is a guide to the properselection of the appropriateComponent Group. It will beobserved that in addition to the flowcharacteristics of a material,consideration must be given to thematerial size, its abrasiveness andits corrosiveness as these determineconstruction details.

For example, if the material has

suitable flow characteristics, is of aclassification Code Size B, has anabrasive number of 5 and is non-corrosive, the Component GroupNumber is 1. If babbitted or bronzebearings, 1A; or for balI bearings,1C. It will be noted that if thematerial is at all corrosive, ballbearings are not recommended.

Having made the ComponentGroup selection, refer to Tables 9,10 and 11, pages 39 and 40, whichgive the specifications of the

various sizes of conveyor screws.The tabulated screw numbers inthis table refer to CEMA StandardNo. 300 on Screw Conveyors. Thisstandard gives complete data onthe screws such as the length ofstandard sections, minimum edgethickness of screw flight, bushingdata, bolt size, bolt spacing, etc.


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(1)For very corrosive conditions (codes 6S or 7S) lighter gauge special anti-corrosion materials

may be used.

(2)Ball bearings are not usually recommended for conveyors handling materials partly or whollyfinely ground. (Code A)

(3)Any abrasive material which is flammable, corrosive, or which may contain explosive dust,consult manufacturer for bearing recommendations,

Conveyor screw speeds must beconsidered when using hard ironbearings on hardened coupling shaftsin order to minimize wear and toreduce the squealing noise of dry

metal on metal. The following formulagives maximum recommendedoperating speed:

120N =Shaft diameter in inches

where

N = Maximum operating rpm of screw

For bearing types A, B and C listedabove, the shafting used for thecouplings is AISI C1018 standardcold rolled steel or equal.

For hard iron bearings, the shaftingfor the couplings is usually mediumcarbon steel AISI 1045 and surfacehardened. Suitably hardened alloyshafting also may be used.


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Component Groups


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Horsepower Requirements,Horizontal Screw ConveyorsThe horsepower required to operate a

horizontal screw conveyor is based onproper installation, uniform andregular feed rate to the conveyor andother design criteria as determined inthis catalog.

The following factors determine thehorsepower requirement of a screwconveyor operating under theforegoing conditions.

CE Equivalent capacity in cubicfeet per hour.

e Drive efficiency.Fb Hanger bearing factor. See

Table13.Fd Conveyor diameter factor See

Table 14, page 42.Fm Material factor. See Table 4,

pages 26 thru 34.Fo Overload factor See Figure D,

Page 42.L Total length of conveyor, feet.N Operating speed, rpm.W Apparent density of the

material AS CONVEYED, lbs.per cubic foot. See Table 4,page 26 thru 34.

The horsepower requirement is thetotal of the horsepower to overcomeconveyor friction (HPf) and thehorsepower to transport the materialat the specified rate (HPm) multipliedby the overload factor Fo and dividedby the total drive efficiency e, or:

LN Fd FbHPf =1,000,000

CELWFmHPm =1,000,000

(HPf + HPm) FoMotor HP = ____________e

or use Figure E, page 42, where HPt= (HPf + H Pm).

It is generally accepted practice thatall power transmitting elements of ascrew conveyor be sized and selectedto handle safely the full load motortorque. If, for example, a screwconveyor requires 3.5 horsepower asdetermined by the horsepowerformula, a 5 hp motor must be used

and all power transmitting elementsmust be capable of safely handlingthe full 5 horsepower.

ProblemMaterial . . . . . . . . . . Vermiculate OreWeight . . . . . . . . . . 75-85 1 lbs/ft3

Capacity . . . . . . . . . . 1200 ft 3 /hrMax. Lump. . . . . . . . 1"Length of Conveyor 31'-0"

Refer to Table 4, pages 26 thru 34.The material class is 80D336. Thecomponent series is 2D and thematerial factor Fm is 1.0

Refer to Table 5, page 35, and selecta 16" diameter conveyor @ 30%loading capable of 1400 ft3 /hr at amax. speed of 45 rpm. Capacity ofunit is 31.2 ft3 /hr at 1 rpm.

120N = ___ = 40 rpm; 39 rpm satisfactory3

LN Fd Fb 3l x 39 x lO6 x 4.4HP1 = ________ = = 0.561,000,000 1,000,000

CE LW Fm 1200 x 31 x 85 x 1.0HPm = _________= = 3.16

1,000,000 1,000,000

(HPf + HPm)x Fo (0.56 + 3.16)1.21MHP = _______________ = = 5.28 use 71 / 2e .85

or use Figure E, page 42, HP1 = 0.56 +3.16 = 3.72 Use 7 1/2 hp.

HP x 63,000 7.5 x 63,000Torque = __________ T = __________ T = 12,115 in. lb.N 39

Table 15, page 43, indicates a 2-bolt connection is rated 16,400 in. lb.

1200Required speed = ____31.2 =38.46

call 39 rpm.

Table 8, page 38, indicates a hardhanger bearing.

Component series 2D indicates HeService Table 10, page 39.

16H614 helicoid screw flight - 3"diameter shaft 3 / 16 "trough and 14 gcover.

Max. speed for 3" diameter shaftusing hard iron bearings.

=

==

=

=

=

===


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Factor F0 and A Drive Efficiency of 85% Are included.

Figure E


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Torsional Ratings of

Conveyor Screw Parts

Screw conveyors are limited in overalllength by the amount of torque thatcan be safely transmitted through thepipes and couplings.

Table 15 combines the varioustorsional ratings of bolts, couplingsand pipes so that it is easy tocompare the torsional ratings of all thestressed parts of standard conveyorscrews. The table conforms to theCEMA Screw Conveyor Standard No.

300. The torsional values are confinedto the sizes listed in that standard.

The lowest torsional rating figure forany given size of coupling will be theone that governs how muchhorsepower may be safelytransmitted. For example, usingstandard unhardened two boltcoupling shafts, the limiting torsionallength of each part is indicated inTable 15.

Thus it can be seen that the shaft itselfis the limiting factor on 1," 11 / 2," and 2"

couplings. The bolts in shear are thelimiting factors on the 27 / 16," couplingand on the 3" coupling used inconjunction with 4" pipe. The bolts inbearing are the limiting factors for the3" coupling used in conjunction with31 / 2" pipe, and for the 3 / 16" coupling.

63025 x HPTorque, TQ = _________rpm

If coupling bolt shear is the limitingtorsional rating, high strength bolts

may be substituted. When using highstrength bolts the limiting factor will, inall cases, be either the coupling shaftor the bearing value, and both mustbe checked.

Screw Conveyor End Thrust

Most screw conveyors can bedesigned with little thought given tothrust as the thrust force in anordinary screw conveyor is moderateand commonly used screw conveyordrives will accommodate thrust ineither direction. However, in screwfeeders with long inlet openings and inscrews used to compress material(either by design or by accident whendischarge openings are plugged)thrust forces can be very severe.Severe thrust forces can strip the

flights from the pipe, stall the drive,result in sheared coupling bolts orfractured couplings and shaft.

The direction of thrust in a screwconveyor or feeder is opposite to tdirection of flow of the product. It ispreferred to accommodate the thruat the discharge end as this resultsthe line of screws and couplings bin tension.

The most common drives in use toare the so-called screw conveyordrives that are adaptations of shaftmounted reducers. These includedrive shafts that are secured in thereducer so as to take thrust in eithdirection and transfer the thrust forto one of the hollow shaft bearingsthe reducer.


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CONVEYOR SCREW DEFLECTION

Deflections of conveyor screws ofstandard lengths not usually a problem.However, if longer than standardsections of screw are to be used,without intermediate hanger bearings,care should be taken to prevent thescrew flights from contacting the troughbecause of excessive deflection. Thenomograph on page 45 indicates thedeflection of standard helicold conveyorscrew sections on schedule 40 andschedule 80 pipe, for various lengths ofscrew sections. The schedule 80 pipemay be needed for large torques.

Applications of screw conveyors inwhich the deflection of the screwexceeds 0.25 inches should be referredo the screw conveyor manufacturer forecommendations. (In some

applications, a deflection of even lesshan 0.25 inches could be critical and

should be referred to the manufacturer.)Very often the problem can be solvedby using a conveyor screw section witha larger diameter pipe. It will be notedrom the nomograph that the use of a

schedule 80 pipe reduces the deflection

very little, hence it isn't practical toeduce deflections by using heavier

pipe. Larger diameter pipe should beused.

Example NO. 1Determine the deflection of a 12H512conveyor screw section mounted on aschedule 40 pipe, with an overallunsupported length of 18 feet. From thenomographic chart, Figure 3.6, thedeflection is greater than 0.25 inch, andherefore indicates that the problem

should be referred to the screw

conveyor manufacturer for solution.

When the flights of the screw aremounted on something other thanSchedule 40 or Schedule 80 steel pipe,such as mechanically drawn tubing orsolid shafting or steel or other metals,he deflection at mid span may be

calculated from the following formula:

5 WL3▲= _____384 El

where:

▲ deflection at mid span, inchesW total weight of screw, lbs.L Length of screw between

bearings, inchesE modulus of elasticity for steelI moment of inertia of hollow or

solid shaft section.

Example NO. 2Determine deflection of a 12H614conveyor screw 20 ft. long. Accordingto manufacturers' catalogues it has aweight of 228 lbs. for an 11’-9’’ longsection and has helicoid flightingmounted on 31 / 2" schedule 40 ironpipe size.

228W = x 20 = 388 lbs.11.75

L = 20 X 12 - 240", L3 = 13.8 X 106

E = 30 X 106I = 4.79 (31 / 2" schedule 40 pipe)

(5) (388) (13-8) (10)6▲ = __________________ = 0.48(384) (30) (10)6 (4.79)

The 0.48 inch deflection is greater thanthe 0.25 inch normally allowabledeflection. Therefore, a larger diameter

pipe or other section having a highermoment of inertia may be tried.

The nomograph on Page 45 will solvesome examples of conveyors longer thanusual or longer than standard lengths.

===

==


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Screw FeedersThis section relates to screw feedershat are used to control the rate of flow

of a bulk material from a bin or hopper.This is limited to the handling of bulkree flowing materials less than 1 / 8" in

size and which are classified asabrasive 5 or 6 as shown in Table 3,page 25.

n screw feeders, the inlet portion of therough is made to be flooded with the

material and by means of a shroud inhe trough, or by the use of a tubularrough, only a controlled amount is

carried to the discharge.

The screws in the feeder are arranged inseveral different ways, depending uponcircumstances. For relatively small inletopenings, the screw often has astandard diameter and pitch. Frequently,however the screw is tapered indiameter with its smallest diameter athe extreme feed end. Screws also maybe made with a constant standarddiameter and a variable pitch, the pitchgrowing larger from the extreme feedend. The purpose of the tapereddiameter or variable pitch screw is to

obtain an even flow from all areas of theeed opening. The capacity of taperedscrews or variable pitch screws isdetermined by the diameter and pitch athe downstream end of the inlet opening.

Several factors should be establishedbefore selecting a screw feeder, thesebeing:

A. Kind and character of materialbeing handled.

B. Density of material as conveyed,lbs/ft3.

C. Maximum rate at which material isto be handled, ft3 /hr.

D. Size consist or screen size analysis.

E. Overall length of feeder, or feederwith extended conveyor, feet.

F. Width and length of inlet opening.

Single screw feeders are mostcommonly used. However, if the inlet

opening is very wide, multiple screwfeeders are more practical.

Single Screw FeedersThe single screw feeder may be aseparate unit, or it may be extendedby sections of normal screw conveyorto any practical length. The procedureby which to choose a single screwfeeder is as follows:

Refer to Material Classification Code,Table 3, page 25, and the MaterialCharacteristics, Table 4, pages 26 thru34. Determine the material code class

and density from Table 4.

Capacity and SpeedFrom Table 16, under the columncaptioned at maximum rpm, find thecapacity which equals or exceeds thedesired feeder capacity. Then findfrom that the feeder diameter and

capacity at one rpm or C,. Divide therequired feeder capacity by C, to obtainthe required speed in rpm.

CN =

Ct

where:

N = Speed of feeder in rpm.

C = Required capacity of feeder, ft3 /hr.

C1 = Capacity at one rpm, ft3 /hr.

This maximum rpm is not absolute buthas been selected as generalrecommended practice. Experience with aparticular set of conditions, or application,may establish slightly different designlimitations. Many factors including bin orhopper design, a subject not coveredhere, will significantly affect screwfeeder performance.

Single Screw Feeder ArrangementThe arrangement and dimensional datafor single screw feeders are shown inFigure F, page 47, and Table 16.

Extension ConveyorThe arrangement of an extensionconveyor, directly connected to a singlescrew feeder, is shown in Figure G,page 47. Obviously the extensionconveyor must operate at the same rpmas the feeder. The size of the extensionconveyor may be obtained by referringto Table 5, page 35. For the code classof the material to be handled find ascrew diameter which will give an equalor greater capacity in cubic feet per hourat one rpm than the C, capacity of the

screw feeder used in the formula todetermine the feeder speed. The degreeof trough loading corresponding to thecode class of material to be handled andits abrasiveness, must not be exceeded.

)Dimensions are typical and approximate. Actual

dimensions should be certified for installation purposes.

)Based on 100% of theoretical capacity with standard

pitch and screw pipe. For nonstandard pitch or pipe

size consult screw conveyor manufacturer.

(3)Maximum in regular construction. Larger inlet

openings require engineering consideration not

covered here.

(4)The length C is equal to two standard pitches.


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Example ofSingle Screw Feeder SelectionProblem:Select a single screw feeder without

extension conveyor for the followingconditions

Material to be handled Salt cake,dry,pulverized

Weight per cubic foot 65-85 lbs

per ft3

Capacity 26 tons(2000lb) perhour = 800cubic feetper hour

Length of feeder, L1 10 feet

nlet opening 40incheslong, 10inches wide

Required is an even rate of flow alonghe whole inlet opening.

Solution:a) From table 4, pages 26 thru 34, salt

cake is code classified at 75 B636 TU

has a component group designation of3-D and a material factor (Fm,) of 1.7.

b) From Table 13, page 41, for aComponent Group D, the hangerbearing factor, Fb = 1.0. Since thisexample does not have a hanger,Fb = 1.0. Use the appropriate factorwhen a hanger bearing or a tailbearing that utilizes a hanger inserttype bearing is used.

(c) To be prudent, for capacitycalculations use the lowest apparentdensity, 65 lbs/ft3.Then the volumefor 26 tons per hour is

(26) (2000) ________ =65

800 ft3 /hr required feed rate.

(d) Referring to Table 16, page 46, a9-inch diameter single screw feeder willhandle 1202 ft3 /hr at a maximum of 65rpm and C1 =18.5 at one rpm. Using theformula for speed.

C 800N = __ = ___ = 43.2 rpmCf 18.5

(e) From Table 17, the equivalent lengthof the feeder is

B CL1 + ___ + ___ in which6 12

B 40L1 = 10, __ = ___ or 6.7, and6 6

C (18)___ = ___ = 1.512 12

Lf = 10 + 6.7 + 1.5 + 18.2 feet

(f) From Table 14, page 42, the“conveyor diameter factor Fd = 31.

(g) Again to be prudent, for powercalculations it is well to use thelargest apparent density forW, so W = 85 lbs/ft3.

L1 N Fd Fb(h) HPa = __________ =1,000,000

(10) (43.2) (31) (1.0)_________________ = .013 HP1,000,000

C W Lf Fm(i) HPb = __________ =1,000,000

(800) (85) (21.5) (1.7)__________________ = 2.10 HP1,000,000

(j) Referring to Figure D, page 42, thefactor Fo depends upon the sum of thehorsepower for friction of the emptyconveyor (feeder in the example) andthe horsepower of

(HPa + HPb) FoHP = _____________ =e

(.013 + 2.10) (1.57)_________________ = 3.90 HP.085

material friction. In this example this sum

is .059 + 2.10 = 2.113 HP and Fo

= 1.57.(k) Then assuming a drive efficiency

(expressed decimally) of 0.85,

Or use Figure E, page 42HPt = (HPa + HPb) = 2.159 MHP = 5

(1) Use a 5 hp electric motor withspeed reduction to 43.2 rpm.

The theoretical estimated powerrequirements calculated in theforegoing example conceivably couldbe exceeded to the extent that the full

5 horsepower of the motor would beused. Therefore, all components ofthe power train, the feeder shaft, thescrew pipe shaft and the screw itselfshould be capable of withstanding-atthe speeds involved for each-thetorsion force or torque of full 5horsepower. See Table 15, page 43for torsional capacities of screwconveyor components.

Effect of Material Loads on ScrewIn many cases, where screw feedersare mounted at the bottoms of bins orhoppers, the screw has to perform itsfunction under heavy loads of materialabove the bin opening or feeder inlet.Under certain conditions and withcertain materials the start-up torquecan be very high, resulting in biggerdrives and heavier feeder components

An alternative solution is the use ofmultiple screw feeders. Multiple screwfeeders may consist of twin, triple, orquadruple screws, side by side to feedmaterials from very wide inlet openings.


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Conveyor Designation SystemScrew diameter & pitch12- = Full Pitch12-8 = 2 / 3 pitch12-6 = 1 / 2 pitch12-4 = 1 / 3 pitch

Coupling diameter3 = 11 / 2"4 = 2"5 = 2 7 / 16"6 = 3"7 = 3 7 / 16"

E = Standard LenEF = RightingF = Flight

Type Conveyor

H = HelicoidHR = Helicold ribbonHS = Hellcoid stainlessHSR = Helicold stainless ribbonS = SectionalSIR = Sectional ribbonSS = Sectional stainlessSSR = Sectional stainless ribbonNOTE: Q prefix on all above types for Quik-Link.

Flight thicknessat outer edge 1 / 64" increments


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component selection

Helicold Flight Conveyor Screws are made of a continuous one-piecehelix fastened to a pipe with spaced intermittent welds. Steel lugs arewelded to pipe and flight at both ends, except on 4-inch size.

Helicoid Flight Conveyor Screw


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component selection

Helicoid Flight

Helicold Flighting is manufactured in a continuous one-piece helix of thedesired diameter, pitch and thickness. The helicold flight is tapered incross section, with the thickness at the inner edge about twice thethickness at the outer edge,


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component selection

Sectional Flight Conveyor Screws consist ofindividual flights formed into a helix. then buttwelded together and fastened to a pipe orshaft with spaced intermittent welds, Steellugs are welded to pipe and flight at bothends, except on regular sectional flight screwsizes larger than 16-inch diameter. Both endsof the pipe have permanent internal collarswith inside diameters to accept couplings,drive shafts or end shafts.

Sectional Flight Conveyor Screw Sectional Flight


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component selection


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component selection

Sectional Flights are individual flights formed into a spiral or helix of thedesired diameter and pitch, butt welded together to form a continuousconveyor screw.


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component selection


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component selection

Ribbon flight conveyor screws consist of sectional flights, butt welded together toform a continuous helix. Flights are secured to the pipe by supporting lugs. Bothends of the pipe have permanent internal collars with inside diameters to acceptcouplings, drive shafts and end shafts.They are used for conveying sticky, gummy or viscous substances, or where thematerial tends to adhere to flighting at the pipe. Stainless steel ribbon flightconveyor screws can be furnished.


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component selection Type 1 Paddles consist of formed steel blades mounted on bolt or rodshanks which are inserted through regular conveyor screw pipe. They arenormally mounted at 120 degree intervals spacing, three paddles perpitch. Paddle at each end of conveyor may be inserted through bolt holein place of regular coupling bolt. Paddle blades may be set at any angleto produce the desired degree of agitation. Paddle conveyor screws areused for mixing, blending or stirring dry or fluid materials.

Drive shafts deliver the driving power, and are designed to provideadequate torque, bending and shear strength, and correct bearingclearances. For extra heavy loads, high carbon steel or heat-treatedalloy steel shafts are used. Jig-drilled coupling bolt holes and accuratelycut keyseats contribute to ease of assembly.

End shafts serve only as support for the last section of conveyorscrew and are furnished of cold-finished steel.


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component selection


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component selection


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component selection

End Lugs are die-formed steel plates welded to both ends of helicoldflighting and to the pipe to strengthen the end of flighting.

Split Flight Couplings permit installing or removing individual conveyorscrews without disturbing adjoining sections. With split flight couplingsinstalled on both sides of each hanger, conveyor screws can be removedwithout disturbing the hangers. The split flight coupling is sturdilyconstructed and jig drilled for coupling bolts.


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component selection

Split Flight Coupling Shafts are used to transmit rotation and to positionaccurately and support the split flight couplings.


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component selection

No. 270 Hangers have formed steel frames and self-aligning ball bearingswhich reduce power consumption and noise levels.


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component selection

No. 216 Hangers have formed steel frames of superior strength and rigidtyand are excellent for heavy service. These hangers are normally furnishedwith hard iron, babbitted: bronze, oil impregnated wood or molded fabricbearinqs, but can also be furnished with special bearings.


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component selection

No. 226 Hangers have a rigid formed steel frame with clearance forpassage of material in large volume. These hangers are normally furnishedwit h hard iron, babbitted, bronze, oil impregnated wood or molded fabricbearings, but can also be furnished with special bearings. Stainless steelframes can be furnished.


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component selection

No. 316 Hangers are similar in construction to No. 216 hangers, exceptthat they are self-adjusting. The top bars are arranged to slide on angleguides fastened to the troughs. These hangers are normally furnished withhard iron, babbitted, bronze, oil impregnated wood or molded fabricbearings, but can also be furnished with special bearings.


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component selection

No. 326 Hangers are similar in construction to No. 226 hangers, exceptthat they are self-adjusting. The top bars are arranged to slide on angleguides fastened to the troughs. These hangers are normally furnished withhard iron, babbitted, bronze, oil impregnated wood or molded fabricbearings, but can also be furnished with special bearings.


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component selection

No. 216F Hangers are similar in construction to No. 216 hangers, exceptthat they are designed for mounting in flared trough. These hangers arenormally furnished with hard iron, babbitted, bronze, oil impregnated woodor molded fabric bearings, but can also be furnished with special bearings.


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component selection

No. 220 Hangers are similar in construction to No. 226 hangers, exceptthat they are mounted on top of the trough angles or flanges. These

hangers are normally furnished with hard iron, babbitted, bronze, oilimpregnated wood or molded fabric bearings, but can also be furnishedwith special bearings. Stainless steel frames can be furnished.

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