21950114 06 MISS Anatomy of the Aggregates Industry

7/28/2019 21950114 06 MISS Anatomy of the Aggregates Industry

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BRYANT PRODUCTS, INC.ANATOMY OF THE AGGREGATES INDUSTRY

INTRODUCTIONThe aggregates industry is in the business of mining and processing rock. The

aggregates industry encompasses rock quarries, sand and gravel plants, concretemanufacturing and asphalt processing facilities; their end products include crushed stone,

sand & gravel, cement and asphalt. These products are used in applications ranging from

road and bridge construction to building construction. The industry produced over 1.7 bil-lion tons of crushed stone and 1.4 billion tons of sand and gravel per year; it represents

over 90% of the non-metallic mining production in the United States. The industry is key

to the growth of world economies, since its products are used in developing the infrastruc-ture required to support economic growth. In addition, a recent development in this

industry is the recycling of asphalt and concrete.

Today, many states require that a percentage of new asphalt and cement contain

recycled material.

In non-technical terms, the aggregates industry turns big rocks into little rocks".

In a typical aggregates processing plant, belt conveyors are the transportation systems,moving the rock products between feeder/breakers, crushers, screens, classifiers,

storage piles and load-out terminals. An aggregates plant cannot operate efficiently

and cost-effectively without belt conveyors providing the material handling.

In this article, we will review the following topics:

a) Products of the aggregates industry

b) An overview of a typical aggregates quarry

c) The applicability of the Bryant Telescoper take-up assembliesto the conveyors in an aggregates quarry

AGGREGATE PRODUCTSThe basic product of the aggregate industry

is rock. Aggregate is defined as any combi-

nation of sand, gravel and crushed stone intheir natural or processed state. The basic

tasks of this industry are to:(1) mine the aggregate

(2) size the material

(3) classify the materials


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Some of the primary products of this industry include:

Coarse Aggregate: This is typically defined as aggregate materials that are retained bya #4 sieve with a 0.187" square opening.

Fine Aggregate: This is aggregate that passes a #4 sieve (0.187" square opening) but ispredominately retained by a #200 sieve.

RipRap: This aggregate product has an average size of between 6" and 30". It is large,irregularly shaped rock and is often used to stabilize slopes or shorelines.

Gravel: This is a granular, pebbly material that results from natural disintegration ofrock. Usually coarser than 1/4" diameter, it is found intermixed with fine sand and clay;

it can be classified as bank, river or pea gravel. Its rounded character is normally

created by the stream action of water.

Base Aggregate: This is crushed rock that is sized for use as the foundation forpavement.

Ballast: This is broken stone or gravel that is often used to stabilize a road orrail bed.

Boulders: Material that is greater than 8" in diameter.

The National Stone Association (NSA) provides the material classification definitions for

the aggregates industry. The above listing is just a sampling of the many categories definedby NSA.

The construction industry is the largest user of aggregate products. Road, bridge,

airport and dam construction account for over 50% of all aggregate products produced inthe United States. Aggregate products are used for sub-base and base materials,

concrete and asphalt for road construction. Building construction, both commercial and

government, represents about 30% of aggregate product usage. The remaining 20% isspread out among residential construction, erosion control and railroad construction.


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THE FLOW OF A TYPICAL QUARRYAs stated earlier, the basic process of an aggregates plant is to turn big rocks into little

rocks". Although the processes to do that are quite technically sophisticated, the basic flowof an aggregates quarry includes A) Mining of the natural rock deposits, B) Feeding,

C) Crushing, D) Screening, E) Classifying, F) Storage, G) Load-out, and H) Conveying.

Figure 1 is a schematic of a typical aggregates plant. It shows the flow of the material

through the various processes in the plant. The symbols shown are used in the aggregates

industry to display each operation.

It is obvious from reviewing the plant layout that conveyor systems are the transportation

systems of an aggregates plant, moving the material from process to process. They are the

most efficient method available for this transportation task.

MINING:The mining of the rock is normally done by blasting out the

natural deposits. This blasting operation is a science in itself,developed by specialists who consider the consistency of the rock,

the depth and the surrounding terrain. The basic process is a) todrill (bore) a series of deep holes in a specific pattern, b) to fill the

holes with explosive material, and c) to detonate the explosives in

a controlled manner.

This blasting process will create a pile of large rocks which must

then be processed into more usable product. Front-end loaderstypically load huge dump trucks, which transport this blasted

material to the processing plant.

In many western states, mining is accomplished by dredging orscraping riverbeds, as this is the source of their aggregate prod-

ucts.

FEEDING:The blasted material is delivered to the processing

area of the plant via the large dump trucks. Thismaterial is dumped into feeder-breakers that prepare

the material for the primary crushers. These feeder-

breakers are extremely heavy-duty devices since they

are subjected to tremendous forces from the impact ofthe dumped rock. They can be static or vibratory, hori-

zontal or inclined. Their job is to feed the rock into the

crusher at the proper rate so as not to overload thecrusher. They are often designed to do some prelimi-

nary sorting", so that smaller pieces of rock can

bypass the crushing operation. The most commonfeeder ahead of the primary crusher is a Grizzly bar

feeder.


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Different types of crushers have been developed for the variety of crushing applications.

The selection of the proper crusher design for a given application is a function of the mate-rial size, material composition (hardness and abrasiveness), the reduction in size required

and the volume of material to be processed.

JAW CRUSHERS are the most universally applicable primary crusher. It is an eccentric jaw,compression machine that works within a 6 to 1 reduction ratio range, accepting rock up to

about 20 in size.

IMPACT CRUSHERS are typically used for limestone or lower abrasive applications. Workingin the 20 to 1 reduction range, these crushers utilize single or double impact impellers.

GYRATORY CRUSHERS are typically used as a primary crusher when high production isrequired.

CONE CRUSHERS are the crushers of choice for most secondary and tertiary crushingapplications, although they can be used as primary crushers in smaller operations.Generally operating in the 6 to 1 reduction ratio range, they generally accept material

up to 4" in size.

HORIZONTAL SECONDARY IMPACT CRUSHERS utilize the benefits of impact crushing to

provide a tighter tolerance product. With reduction ratios of up to 12 to 1, these machinescan handle the more abrasive materials.

ROLL CRUSHERS are compression type machines that are limited to 2-1/2 to 1 reductionratios. They are capable of producing material sizes within close tolerances.

VERTICAL SHAFT IMPACT CRUSHERS combine impacting benefits with high chromemetallurgy. Typically used as a finish crusher, they accept material up to 3" in size and

with high abrasive makeup.

HAMMERMILLS (LIMEMILLS) are typically used in a secondary crushing application withmaterial size up to 8" and provide a reduction ratio of up to 20 to 1.

CRUSHING:Crushing is the operation of sizing the rock. In a typical

aggregates plant, material may go through three crushing

stages, depending on the material to be produced. Each

crushing step further reduces the size of the material. Thecrushing operations are typically defined as

a) Primary Crushing of the mined rock,

b) Secondary Crushing, and

c) Tertiary (third stage) Crushing.


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CRUSHERS

GYRATORY CRUSHERS

JAW CRUSHERS

ROLL CRUSHERS

ROTARY

BREAKER

IMPACT CRUSHERS

Dodge Blake

(double-toggle)Overhead Pivot

(double-toggle)

Overhead Eccentric

(single-toggle)

Hammer Mills Vertical SpindleCageDisintegrators

Impactors

ConeGyradisc

True

Gyratory

Single RollsDouble Rolls


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SCREENING:Screens are the sieves that separate the

aggregates by size. In their simplest form, theyare meshes that allow a certain size material

to drop through, while retaining material that

is too large to pass the mesh opening. They aretypically vibrating devices that are horizontal

or inclined. They are often multi-deck

designs with progressively smaller mesh sizes

on each deck. There are many designs forthese vibrating machines, each attempting to

maximize material separation.

The screen itself can be made from a number of different materials and in a variety of

patterns. Some of the most common are:

WOVEN WIRE CLOTH: This is the most common screening material and is used in all phases

of screening. It is designated by the clearance in the mesh or by its square mesh (definedas the number of openings in one inch). The openings are typically either square or rectan-

gular, and can be weaved in a variety of manners. Wires used to manufacture woven wirecloth are usually steel alloys, copper alloys, nickel alloys or stainless steels.

PLASTICS: Plastics can we woven similar to wire cloth. They are commonly used in thechemical industry due to their corrosion resistance. They are best suited for light materialswith low abrasion.

PROFILE DECKS: This is a screening medium consisting of wires in various shapes, runningsubstantially parallel to each other. They are used primarily in dewatering applicationsand for small particle separation.

ROD DECKS: These decks are constructed of round rods arranged parallel to each other.They are designed to handle high volumes of wet or dry abrasive materials.

GRIZZLY BARS: This is a heavy duty screening surface consisting of spaced bar, rail or pipemembers running in the direction of material flow. The bars can be either cast or fabri-cated, and are used for sizing with openings greater than 1-1/2". They are primarily used in

heavy-duty operations ahead of the primary crusher, where accuracy of separation is not

important; they are extremely effective with very abrasive materials.

PERFORATED PLATE: These screens are used when the material being screened is heavy orhighly abrasive. They are available in a wide variety of opening shapes and sizes, and are

constructed from a variety of materials, including steel, bronze, brass, copper and alu-

minum. They can also be cast rather than fabricated. Some applications require a rubbercladding for extra abrasion resistance.

PERFORATED RUBBER or POLYURETHANE DECKS: Similar to perforated plate decks, thesescreens are made from rubber or polyurethane materials. They both offer the advantage of

increased abrasion and impact resistance.

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The major advantages of the standard Bryant Telescoper are

Elimination of adjuster rod thread damage due to rust, corrosion and material build-up

Elimination of take-up assembly freeze up due to its truly protected screw design

Rigid structure due to the tube sizes utilized and close tolerances achieved

Allows utilization of standard pillow block bearings both 2 bolt and 4 bolt types

resulting in lower bearing cost, easier bearing change-out and, therefore, reducedmaintenance costs

Longer life expectancy than other manual take-up devices

Simple mounting to the conveyor frame: standard feet, mounting studs or direct weld

Easily customized to customer's unique requirements

Powder coat finish for durability

Use of ACME threaded rod on Series 350HD, 400 and 500 units for high load and

thrust capacity

Pinned Adjustment Nut design on Series 350HD, 400 and 500 units for higher

adjustment torque and easier disassembly

SPRING COMPRESSION TELESCOPERS

Bryant Products has developed a spring compression version of their popular BryantTelescoper take-up assembly. The Bryant Spring Compression Telescoper

automatically compensates for belt stretch and wear through a unique design utilizing acompression spring within the tube assembly. By selecting the proper spring size and rate,

the thrust capacity of the Bryant Telescoper can be matched to the customer's specificapplication. On Series 300, 350HD, 400 and 500, Bryant Spring CompressionTelescopers are fitted with a direct reading tension scale". This feature allows accuratedetermination of belt tension by relating the amount of spring compression and the

selected spring compression rate.

Users specify a Bryant Spring Compression Telescoper when they

Require automatic compensation for belt stretch and wear

Require constant belt tension under varying thermal conditions

Require accurate determination of actual belt tension at the tail pulley

Require absorption of shock and impact loads

The Bryant SpringCompressionTelescoper provides a

major advantage overconventional manual

take-up devices: it canbe adjusted by the

conveyor user to

provide a specificslack-side belt tension.


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CLASSIFYING:Almost all aggregate products contain finesor sands. Classifying equipment is

designed to separate the fines from the aggregates, dewater it and separate the fines bysize.

Water is used in the aggregate processing to wash the rocks/stones throughout the plant.The water cleans away the sand (fines) into classifying tanks. These systems are designed

to separate (classify) the sand by size and to remove the water. There are a number of dif-

ferent ways to perform this classifying; the most common method is to utilize a screw

type classifier. They are normally an inclined trough or box. The screw flight turns withinthe trough, conveying the material up the incline. The discs on the flight have holes in

them, which allows the water to separate and flow downhill. The sand is then separated by

size by running it through a series of sieves of varying size.

STORAGE:Once the aggregates and fines are sized, they are conveyed to storage areas to await deliv-

ery to the end customer. Storage is typically done in (a) open piles, (b) silos or (c) bins. They

are simply staging areas for the various materials.

LOAD OUT FACILITIES:Loading out the products of a typical aggregates plant entails (a) weighing/measuring the

material and (b) conveying it into the transportation vehicle. Load out is typically accom-plished with a front-end loader, by bin release or by conveyor. Transportation vehicles

include trucks, trains, barges and ships.


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BELT CONVEYORS:As stated earlier, conveyors are the transportation systems of an aggregate plant. They movethe various materials along between the crushers, screens, classifiers, storage facilities andload out. An aggregates plant could not efficiently operate without conveyors.

Belt conveyors have attained a favored position in transporting bulk materials due to their

economy, reliability, safety, versatility and almost unlimited range of capacities. They canconvey a wide variety of materials, from fine dusty chemicals to large lumpy ore. Belt con-veyors can operate continuously, offering an economy of scale dramatically superior totrucks or other forms of haulage.

The Conveyor Equipment Manufacturers Association (CEMA) has played an important rolein the development of standards for the design of conveyor systems. Their Belt Conveyorsfor Bulk Materials manual has become the accepted reference for conveyor designersworldwide. In addition, the technical committees within CEMA have developed rigorousstandards for the design and manufacture of many belt conveyor components, most notablyconveyor pulleys and idlers.

Belt conveyors can be designed to follow an almost unlimited number of profiles (paths of travel).They can be horizontal, inclined, or declined, and even incorporate curves. In addition, they canbe configured for a variety of loading and unloading conditions. The proper design of a beltconveyor requires an understanding of the characteristics of the material to be handled, since itsbehavior while being carried, loaded and discharged affects the conveyor's design.

In its simplest terms, a conveyor can be described by its rated capacity; that is, the totalweight of material that it can convey in one hour. This is commonly referred to as theconveyor's Tons per Hour (TPH) capacity; it assumes a conveyor belt carrying a uniformcross section of material and traveling at a uniform speed. This TPH capacity is a functionof the belt width, the troughing angle of the idlers/belt and the speed that the belt ismoving, normally described in feet per minute (FPM)". As any (or all) of these factors

increase, the capacity of the conveyor will increase. However, there are limits for beltwidth, troughing angle and belt speed; they are both independent and interdependent. Theconveyor designer's task is to find the best combination of these factors for the optimumconveyor design for their given application. Sounds simple but conveyor design becomesa series of iterations and compromises to find that best design.

Once the basic parameters of belt width, troughing angle and belt speed have beenselected, there are a number of other decisions that the designer must make. Included inthis process is the selection of

a) The conveyor belt,

b) The idlers,

c) The pulleys, shafts and bearing assemblies,d) The conveyor drive mechanism (motor, gear reducer, etc),

e) The conveyor control system,

f) The belt take-up system, and

g) The miscellaneous equipment, such as belt cleaners, skirtboards,loading chutes, safety devices, etc.

Most of these selections are inter-related; as such, modern conveyor design is an iterativeprocess. Many combinations of these components are evaluated, typically by high-speedcomputers, to hone in on the optimum package.


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CONVEYOR TAKE-UP SYSTEMS:All properly designed conveyor systems require some type of take-up device.

The purpose of a take-up system is

a) To insure the proper amount of slackside tension (T2) at the drive

pulley to prevent belt slippage,

b) To insure proper belt tension at loading and other points along theconveyor, so as to prevent the loss of troughing contour of the belt between

idlers, thus avoiding spillage of the material from the belt,

c) To compensate for changes in belt length due to belt stretch, and

d) To allow belt storage for making replacement splices.

Any conveyor can be expected to have stretch in the conveyor belt. Some belt stretch is

temporary, often due to changes in the belt tensions caused by starting or brakingconditions, or caused by changing thermal conditions. Other belt stretch is permanent,

caused by elongation in the fibers and fabrics used in the belt construction. Take-up sys-

tems allow the conveyor designer to compensate for these changes in overall belt lengthwithout having to cut out sections of the belt.

The required distance of take-up movement is a function of several factors, including

a) The type of starting or braking that is employed in the conveyor. Across-

the-line motor starting requires more take-up movement thana controlled soft start,

b) The number of starts and stops with the belt fully loaded,

c) Elongation characteristics of the conveyor belt, and

d) The running tensions of the conveyor system.

The take-up system should provide sufficient movement to accommodate acceleration ordeceleration surges without having the take-up strike against its stops. It should also allow

for some storage of belting, in case the belt must be repaired. The design of the take-up

system should ensure its smooth movement and even tension across the face of the belt.

There are two basic types of take-up systems used on belt conveyors:

(1) Manual take-up systems, and

(2) Automatic take-up systems.


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MANUAL TAKE-UPS:Typically used on conveyors up to 100 feet in length, manual systems have the advantage

of compactness and low cost. Manual take-ups are recommended where an automatictake-up is not practical because of space limitations or because of cost.

The major limitation of most manual take-up systems is the infrequency of manual reten-

sioning. This creates a situation where the belt is either tensioned too tight or too loosemost of the time. In addition, most manual take-up devices do not offer a way to monitor

belt tension, so the operator does not really know how much belt tension he has. Because of

this limitation, most conveyor designers will apply a service factor of 1.3 to 1.5 whenselecting tail pulley/shaft/bearing sizes. This is to compensate for the additional tension

that commonly occurs with manual take-up systems.

The most common type of manual take-up is the screw take-up. They utilize a threaded rodthat moves the bearing or a bearing mounting surface through the take-up travel. Manual

screw take-ups are typically available in industry standard travel lengths, such as 12, 18,

24, 30 and 36 inches. However, take-up manufacturers frequently build special screw

take-ups in different travel lengths.Most manual screw type take-up devices are prone to freeze-ups as material spillage

and corrosion attack the adjusting screw mechanism; after a short period of operation,many frame designs become almost impossible to adjust due to damage to the adjusting

screw. In addition, most manual take-up devices require the use of special take-up

bearings, which fit only into a particular manufacturer's take-up frame. These guide railmounted take-up bearings are more expensive than the more common pillow block

bearings used on most conveyor pulley assemblies in a belt conveyor.

As stated previously, the main problem with manual take-ups is that they require frequentattention from a trained maintenance person. Evaluation must be made as to whether the

conveyor requires additional take-up action, and then the operator must adjust the manualtake-up to the proper tension. Most manual screw take-ups do not have a gauge or index toguide the operator in this tensioning process. It becomes a hit or miss process, and the

tendency is to overtension the belt. This overtensioning, if severe enough, has the potential

to cause component failures in the conveyor; pulleys are especially susceptible to overten-sioning of the screw take-ups.

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Manual take-ups are almost always used at the tail end of the conveyor, at the oppositeend from the drive pulley. Most conveyors using screw take-ups are simple, two or three

pulley systems.

There are a variety of screw take-up styles available from a number of manufacturers.

These styles include:

a) Heavy Duty, Protected Screw Take-up Frames:These frames are typically of a welded and bolted steel

construction, with an adjusting screw that is somewhat

protected under an angle iron member. They typicallyaccept a variety of pillow block bearing types, bore sizes

and are available in various travel lengths.

b) Light Duty, Protected Screw Take-up Frames:Similar to heavy duty frames, they are designed as an

economical frame for lighter conveyors. Accepting ball,

tapered roller, spherical roller and sleeve pillow block

bearings, they offer an adjusting screw protected fromfalling material by an angle iron member.

c) Center Pull Take-up Frames:Center pull frames are of welded steel construction

with reinforced steel end plates. The hinged cap rail

allows access for bearing installation. They require aspecial style bearing available from most major bearing

manufacturers.

d) Top Angle Take-up Frames:Top angle frames are of welded steel construction, with

the adjusting screw normally plated to resist corrosion.The screw is protected from falling material by the toprail. They accept a variety of manufacturer's special

take-up bearings, with a typical bore range of 1-3/4"

through 4".

e) Wide Slot Side Mount Take-up Frames:Used with ball bearings, this style frame provides a

compact solution to belt tensioning. They accept a vari-ety of manufacturer's bearing cartridges, with a bore

range of 1/2" through 3-1/2".

f) Bryant Telescoper Take-up Frames:These frames utilize an adjusting screw enclosed within

two or more telescoping steel tubes. Pillow block bear-

ings are typically mounted to the inner tube whichtelescopes out of the outer tube via the action of the

adjusting screw. This design virtually eliminates con-

tamination reaching the screw assembly,due to the screw being completely

protected within the

telescoping tubes.


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AUTOMATIC TAKE-UPS:Automatic take-ups are the preferred

method for maintaining belt tensionin most belt conveyors over 100 feet

in length. They can be installed hori-

zontally, vertically or on an incline.They are typically gravity operated,

although there are power operated

systems utilizing hydraulic, electric

or pneumatic mechanisms. The mostcommon type of automatic take-up

system is a gravity take-up, which

utilizes a heavy counterweight hang-ing from a take-up pulley carriage.

The conveyor designer has three key decisions to make relative to an automatic take-up

system:

1) Location of the take-up system within the conveyor,

2) The amount of weight (or force) required for proper operation, and

3) The amount of take-up travel required.

Automatic take-ups can be located at almost any place on the return run of the conveyorbelt. The key factor in take-up system location is to try to keep belt tension at a minimum;

this entails keeping the take-up system as close to the drive pulley as possible. Ease of

maintenance access and economics are other considerations to take-up location.

On long, horizontal or inclined conveyors, the gravity take-up should be located near the

drive, where it will act quickly enough to prevent slippage of the belt on the drive pulley

during acceleration at startup. An automatic gravity take-up system must provide a forceequal to twice the required belt tension at the location of the take-up. This force is usually

supplied by a counterweight made of steel, concrete, cast iron or some other heavy mate-

rial. If a system of wire ropes and pulleys are used to suspend this counterweight, theirmechanical effect must be factored into the

calculation of the hanging weight. Gravity

take-up counterweights are typically con-structed such that weight can be added or

removed as conveyor operating conditions

change.


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Gravity take-up system movement (or travel) is determined by (a) the conveyor center-to-center distance, (b) the construction of the conveyor belt, (c) environmental conditions, and

(d) amount of belt storage required. CEMA has developed some recommended values of

take-up movement for automatic take-up systems.

Not all automatic take-up systems utilize a counterweight. Systems utilizing electric cable

drum drives with tension sensing devices are often used in applications where verticalspace is at a premium. The take-up pulley is bolted to a sliding carriage that is attached to

the cable tensioning system. Based on outputs from the tension monitors, the cable drum

drive adjusts the cable length, thus increasing or decreasing the belt tension. Hydraulicand pneumatic automatic take-up systems utilize hydraulic or pneumatic cylinders to

increase or decrease the belt tension based on similar sensor information.

There are some manual take-up devices that deliver many of the advantages of an auto-matic take-up system. The Bryant Spring Compression Telescoper and the BryantHydraulic Telescoper are systems that meet this criteria. These devices provide theconveyor user with the ability to (a) set the belt slack-side tension at a specific value,(b) compensate for transient loads through their shock absorption capabilities, and

(c) compensate for belt stretch.


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BRYANT TELESCOPER

The Bryant Telescoper represents an innovative approach to manual belt tensioning.

The unique design eliminates the biggest shortcomings of other manual take-up devices:

freeze up of the screw assembly,

the need for special take-up bearings, and difficulty of bearing maintenance/replacement.

The Bryant Telescoper utilizes a tube within a tube approach with the adjusting screw

totally enclosed within the tubes. This design virtually eliminates contamination reaching

the screw assembly. Fitted with the optional grease fitting, Bryant guaranteesno freeze up conditions for five years.

STANDARD TELESCOPER

The standard Bryant Telescoper consists of a three piece modular construction, including:

The outer tube body assembly, which mounts to the conveyor frame,

The inner tube slider assembly, which includes the floating adjuster nutassembly and the pillow block bearing mounting plate, and

The adjuster assembly with the threaded adjusting rod factory treated with

anti-seize compound prior to assembly.

The slider assembly telescopes within the outer body tube as the adjuster rod is rotated.Due to the close tolerances of the mating tubes, the Bryant Telescoper offers a smooth,non-binding operation of the take-up over its entire adjustment range.

With the optional grease zerk fitting installed, the design provides a lubricant reservoir

within the slider tube to provide additional protection for the threaded adjuster rod assem-

bly. In addition, the slider tube is ported to allow grease to flow into the area of slider/body interface. This provides a grease barrier to the ingress of outside contaminants.Grease zerk fitted Bryant Telescopers are recommended for those especially dirty envi-ronments typically found in many aggregates operations and/or where conveyor

washdowns are common.


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THE HYDRAULIC TELESCOPER

For the higher belt tension applications that are becoming more common in aggregates

mining applications, Bryant has developed a line ofHydraulic Telescopers, utilizing theproven features of their dependable Telescoper take-up assembly. Designed with a noleak hydraulic cylinder, the Bryant Hydraulic Telescoper offers a compact design with

the cylinder totally enclosed within the tubes for safety and protection from contamination.All units are fitted with pressure gauges for accurate monitoring of hydraulic pressure and

belt tension. Bryant offers the Hydraulic Telescoper as a stand alone unit, or with anengineered hydraulic power system.

Advantages of the BryantHydraulic Telescoper include

Remote actuation of the devices

Accurate determination and

monitoring of belt tension

Automatic compensation for beltwear and stretch

Easy tensioning of high tension

conveyor systems

THE TOP MOUNT TELESCOPER

The Bryant Top Mount Telescoper is the newest addition to their take-up line. TheBryant Top Mount Telescoper places the pillow block bearing mount over the tubewhile the threaded adjustment rod remains completely protected within the body tube. Therod is protected from material build-up, rust, corrosion and thread damage common to

aggregate industry applications.

In fact, the Bryant Top MountTelescoper was specifically devel-oped for the tough applications of

aggregate industry conveyor sys-tems. Available in models 350TM,

400TM and 500TM, the Bryant

Top Mount Telescoper accom-modates pillow block bearings up to

6" bore. The Bryant Top MountTelescoper is designed to mountwithin the side frame of mostaggregate industry conveyors.

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BRYANT TELESCOPERS IN AGGREGATE APPLICATIONSAs we have seen from the information presented above, an aggregates plant is made up of

a multitude of processes, all connected by a material transportation system consisting oftrucks and conveyors. This transportation system moves the processed material around the

facility and eventually out to the customer. Conveyors are an important part of these facili-

ties, and their trouble free operation is critical to the successful and profitable operation ofan aggregates quarry.

Referring to Figure 1, we can view schematically a typical aggregates quarry. It shows the

movement and processing of the rock from the truck dump into the primary crusher (upperleft) through to the load-out of trucks carrying the finished products to the end customers

(lower right). The conveyors utilized in this plant include:

48" Primary Conveyortakes the output of the Grizzly feeder and/or primary jaw crusher to asurge pile and/or the Rip-Rap storage pile. This will typically be the highest horsepower

conveyor in the facility, driven by a 100 horsepower or larger motor. It is an incline con-

veyor, typically 150 feet or more in length, and is equipped with a gravity type automatictake-up system.

36" Conveyor A runs from under the primary crusher surge pile to the 6 x 16 2D screen.This is an inclined conveyor, normally between 25 to 100 horsepower, that utilizes a gravity

type automatic take-up system.

36" Conveyor B carries the output from the screen and/or the secondary cone crusher upto the 9 x 24 3D secondary screen. This is also an inclined conveyor, normally between

50 to 100 horsepower, that utilizes a gravity type automatic take-up system.

24" Conveyor E-1 carries the output of the secondary screen to the 24" ConveyorE-5 that feeds onto Conveyor D"; it also moves material to the overflow chute that feedsConveyor E-2". This conveyor is under 100 feet in length, under 25 horsepower, and uti-lizes a manual screw type take-up system.

24" Conveyor E-2 takes the overflow material from Conveyor E-1 to the fines stock pile.This is an inclined conveyor, probably under 25 horsepower. It utilizes either a gravity

take-up system or a manual take-up system, determined by the traffic flow under this con-

veyor.

24" Conveyor E-5 also moves the overflow material from Conveyor E-1 to Conveyor D

for reprocessing through the secondary screen. This is a short inclined conveyor, less than25 horsepower, utilizing a manual take-up system.


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30" Conveyor D carries the sorted material from the secondary screen and thetertiary (third stage) crushers back up to Conveyor B for reprocessing through the

secondary screen. This is likely an inclined conveyor of under 25 horsepower utilizing a

gravity take-up system.

24" Conveyor F moves material from a feeder hopper into the surge bins adjacent to thesecondary screen. It is a relatively short conveyor, under 25 horsepower, equipped with amanual take-up system.

30" Conveyor C takes the output of the secondary screen to the third stage screen, forfinal sorting of the material before placement in the load-out bins. This conveyor is an

inclined belt, with between 25 to 50 horsepower. It is equipped with a gravity type auto-

matic take-up system.

24" Conveyors E-3 and E-4 move material from the overflow chute of Conveyor E-1through the screw classifier to the washed screenings stockpile. These conveyors are usu-

ally under 100 feet in length, under 25 horsepower, and utilize manual type take-upsystems.

36" Load-Out Conveyors LO-1 and LO-2 run from the load-out bins to the transporttrucks. They are horizontal conveyors with 25 or less horsepower, utilizing manual

take-up systems.

30" Conveyors CR-1 and CR-2 move material from the output of the primary screen to thecrusher run storage pile. They are inclined conveyors, under 25 horsepower, which can

utilize either automatic or manual take-up systems.

30" Conveyors PM-1 and PM-2 move material from either the fines stock pile or thecrusher run stock pile into the pugmill for processing. These conveyors arenormally short in length, under 25 horsepower, and utilize manual take-up systems.

All of the conveyors that utilize manual take-up systems are candidates for BryantTelescoper take-up systems. The determination of which Bryant Telescoper model isapplicable can be a function of the conveyor frame configuration, the bearing size,

environmental and operational considerations and the operator's preference. The original

Standard Bryant Telescoper, the Bryant Spring Compression Telescoper, theBryant Hydraulic Telescoper and the Bryant Top Mount Telescoper have all beenused on aggregate industry conveyors.

19


20/24

The aggregates industry has some of the most demanding applications for belt conveyors inindustry today. The production, environmental and cost requirements of the industry

requires careful selection of conveyor components that will meet their needs. The BryantTelescoper is a product that continues to meet and exceed the challenges of the aggre-gates industry. The advantages of the Bryant Telescoper are:

Long life due to rigid, protected screw design

Reduced maintenance costs through utilization of pillow block bearings

Cost effective design

Modular design offering customized configurations

Spring Compression Model for accurate tensioning

Hydraulic Model for extra tough applications

Top Mount Model for fitment to most conveyor frames

Backed by a No Freeze Up warranty

SUMMARYThe aggregates industry provides our economy with the raw materials required for infra-

structure development, such as the construction of roads, bridges, railbeds, buildings and amultitude of other uses. Conveyors are the lifelines of aggregate processing plants, effi-

ciently moving the mined rock between crushers, screens, classifying screws, surge piles,

storage bins and load-out facilities. Bryant Products Inc. provides a high performance,dependable take-up system that insures long life and trouble free operation for the plant

operators.


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21

FINES STOCK PILE

AND TUNNEL WITH

PAN FEEDER

CRUSHER RUN

STOCKPILE

DUMP POINT

PRIMARYGRIZZLYFEEDER

CONV.PM-2

24"

CONV.PM

-130"

CEMENT SILO

AND BAGHOUSE

CEMENT

METERING

SYSTEM

PUGMILL

6X16 3D

TERIARTY

SCREENS

PRIMARY

JAW CRUSHER

RIP - RAP

CLASS 1

SURGE PILE AND TUNNELWITH FEEDER

PRIM

ARYCON

V.48"

600TPH

CONV.CR-1

CON

V.A36"

600TP

H

CONV. CR-2 30"

FINES STOCK PILE

AND TUNNEL WITH

PAN FEEDER

TRANSPORT

TRUCK

FIGURE 1


22/24

CONV. E-2 24"

6X16 2D

PRIMARYSCREEN

SECONDARY

FEEDER

SECONDARY

CONE CRUSHER

FINES

STOCK

PILE

CONV. E - 24"160

TPH

CONV.E-5 24"250TPH

300 TPHTERTIARY

CRUSHERS

CONV. D 30"

200 TPH

9X24 3D

SECONDARY

SCREEN

FEEDER

HOPPER

CONV.F.24"250 TPH

54 X 32 SCREW

CLASSIFIERCON

V. E-4

24"

WASHED

SCREENINGS

STOCK PILE

CONV. LO - 1 36"

CONV. LO - 2 36"

SURGE

BIN

CONV.

B36"

1000

TPH

CONV.C 400TPH30"

CONV.E

-324"

160TPH

SURGE BINSFEEDER

HOPPER

OVER

FLOW

CHUTE

TERTIARY

FEEDERS

TRANSPORT

TRUCKS

LOAD OUT

BINS

400 TPH


23/24

Table of Contents

- Introduction PG. 1-2

- Flow of a Typical Quarry PG. 3-7

- Belt Conveyors PG. 8

- Conveyor Take-up Systems PG. 9-13

- Bryant Telescoper PG. 14-16

- Bryant Telescoper inAggregate Applications PG. 17-19

- Aggregate Chart PG. 20-21


24/24

NEW! AirFormTM Tapered SteelConveyor Rollers

Greatly improved TIR, angle of taperand bearing pocket accuracy.

Diameters to 8", lengths to 60", up to10 gauge material with or withoutdrive belt grooves.

Our tapered steel rollers require notooling so special profiles and tapersare available.

TeletrackTM Conveyor Rollers

Thermoplastic designs available inPVC, Nylon, Polypropylene, andUHMW (some materials available withsteel reinforcing for higher loadcapacities).

Low carbon steel, pre-plated steel andstainless available in a variety of wallthickness and pipe sizes - diametersfrom 11/16" to 6".

All common bearing options - plasticrace, sealed precision, UHMW orwood sleeve, stamped steel/fullcomplement - available with orwithout axles in a variety of sizes andforms.

Telescoper

Takeups

Available in low carbon or stainlesssteel.

Only takeup with a fully protectedadjustment rod.

Guaranteed to adjust in anyenvironment for up to 5 years.

Simple modular design allows for awide range of readily available options.

Standard products shipped same dayfrom factory.

Optional constructions and specialdesigns available in one week leadtime or less.

TeletrackTM Custom Conveyor

Frame Components

All components engineered and built to

order.

Available in one week lead time or less.

Side rails, leveling feet, belt and drive

guards.

Our Products, Services and Tradenames....

FOOD PROCESSING (FIELD HANDLING, PREPARATION, PACKAGING),

AGGREGATES, CONCRETE, ASPHALT, MINING, ORE CARRYING, UNIT HANDLING CONVEYOR

SYSTEMS, WASTE MANAGEMENT & RECYCLING, CONVEYOR TURNS, FERTILIZER & PHOSPHATE

PRODUCTION, CHEMICAL PROCESSING.

Custom Machining & Fabricating

Full CNC machining and programming

- CAD and solid modeling capabilities.

CNC Lathes - bar feed and chucking-

lengths to 60", diameters to 14",

tolerances to .0004".CNC Vertical Machining - 20" by 48"

swing, tolerances to .0004".

MIG and TIG Welding - low carbon,

stainless and aluminum.

Tube forming and fabricating, press

and CNC sawing.

TeletrackTM Conveyor PulleysAvailable in PVC, UHMW, stainless or

low carbon steel in a wide array oftubing and pipe sizes.

Diameters to 10", lengths to 60".

Straight, crowned or trapezoidal faceconfigurations - lagging in rubber,white rubber or polyurethane.

Machined face or NEW high precisionformed face process that meetsmachined tolerances without the cost.Bryant offers the only forming processcapable of producing trapezoidalcrowns.

Fixed shaft, through hole precisionbearing with or without labyrinth and

dust seals, QD or XT type hubs.

800 825 3874

QUALITY CONVEYOR COMPONENTS

FPM&SA

MEMBER

21950114 06 MISS Anatomy of the Aggregates Industry

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