Material Handling Flashcards
Three sections of a belt
Top cover (thicker)
Bottom cover
Carcass (provides strength)
Main types of belt carcasses
Solid woven
Reduced-ply
Multiple-ply
Steel cord
Single-ply of fabric with interlocking weaves, avoids the potential problem of separation of plies
Solid woven
Wider plies separation between each layer, plies come to the edge of the belt.
Reduced-ply (high-tensile synthetic fibre)
Usually more than 3 layers of woven materials. Strength, load, and tension vary with the number of plies and fabric used
Multiple-ply (no more than 8 plys)
Single layer of cables embedded in belt. Used where extreme operating tension is constant, or take-up travel limited
Steel Cord (cables 3-12mm in diameter)
4 types of mechanical fasteners
Hinged plate
Bolted plate
Wire clip
Alligator
The strongest and preferred type of splice
Hot vulcanized (steel cable is the main tension element in belt, 90% belt strength)
These pulleys should only be used where the approach to the pulley has an unsupported section which is unaffected by the training idlers
Crowned pulleys
The largest diameter pulley, primarily used to reduce flexing in the tensioned belt
Head pulley
Drive pulley used on the dirty side of the belt used to increased friction, lower belt tension. Reduced slippage in wet conditions, increased life for both belt and pulley
Lagged drive pulley
Pulleys without lagging, standard steel drums used with normal fabric ply belts
Smooth pulleys
These pulleys prevent the build-up of debris under the belt
Self-cleaning pulleys (wing)
The main purpose of this pulley is to return the belt
Tail pulley (smaller than head or drive pulleys)
This pulley increases the arc of contact on the drive pulley
Snub pulley
Pulley used to change the direction of the belt
Bend pulley
2 basic types of idlers
carrying - support the loaded run of the conveyor belt
return - support the empty run of the conveyor belt
Carrying idlers used where bulk materials are likely to spill, are tilted forward 2 degrees in direction of belt travel. These Idlers use 3 rolls, outside rolls are inclined at 20, 35, or 45 degrees
Troughing idlers
These carrying idlers are connected or linked together by cable or flexible joints
Suspended idlers (catenary) - usually 3 roll, 5 roll may be used in the load section
carrying idlers used when the belt is to be troughed
Transition idlers - the deeper the trough, the larger the transition distance
Carrying idler found in the manufacturing processes where the removal and placement of goods at various points is desirable and spillage not a concern
Flat-belt carrying idler
Guide idlers installed on a troughed conveyor to assist in training the belt should the belt begin to move
Rigid side-guide idlers - mounted a few inches from edge of the belt, mounted near pulleys (guidlers)
These return idlers used where the conveyed material will adhere to the belt and rolls
Self-cleaning rubber disk idlers
Return idler deigned specifically for minor belt self-alignment, not for general alignment, used on both load and return side of conveyor
Self-alignment (training) idlers
These training idlers rest on a pivot in the centre of the frame
Troughed-belt training idlers
These idlers are used at the loading points of the conveyor and protect the belt from damage
Impact idlers (installed as close together as possible)
Type of take-up mounted near the drive pulley, distance between head and tail pulley greater than 100ft
Gravity take-up
Type of take-up used where space is limited and gravity take-up cannot be used
Horizontal (carriage) take-up (placed at any point in conveyor system)
Type of take-up that must be adjusted by hand, and very compact
Screw take-up
When loading a belt in the same direction these 2 basic designs are used
A short (transition) conveyor A chute
This side of belt loading increases belt wear
Side (right-angled) loading
What can be used to change the direction of a load passing between conveyors moving in different directions
Angled transfer chute
Where large lumps are a constant in the material these chutes can be used
grizzlies or screened loading chutes
This is used to contain the material on the load-carrying conveyor until it reaches the carrying belts speed
Skirting (does not come in contact with belt, made of rubber or soft compound, no NOT use old belt)
When belts are to be loaded from bins, hoppers, or piles some sort of _____ must be used
feeder
Type of feeder located at the bottom of a bin and used to control the flow of materials. Not used for lumpy materials
Screw feeder
Feeder that is a very short belt conveyor installed under a bin or hopper used for handling fine materials
Belt feeder
Feeder that uses bars or scrapers attached between two conveyor chains. The bar drags the material along bottom of trough. Suited for materials with small lumps
Drag-scraper feeder
Heavy duty feeders used for handling lumpy, abrasive materials. Made of over-lapping steel plates mounted on heavy chain
Apron feeders
Feeder driven off an eccentric drive which moves the plate back and forth. Material is dropped onto belt
Reciprocating-plate feeder - fine materials, small lumps
Feeder is a simple regulating gate moving up or down outside of a bin or hopper to control flow
Control-gate
This feeder is electrically-powered to vibrate as the material moves through it. Wet sticky materials should not be used
Vibrating feeders
Feeder has a drum with attached wear plates. Small clearance between wear plates and vanes
Rotary-vane (pocket) feeder
Feeder has a smooth rotating drum which controls the flow of small aggregate materials. Material must flow freely
Rotary-drum feeder
Feeder has a flat circular table, material forced off table by a plough
Rotary-table feeder
These are used to discharge material from the belt at various intervals. Used where storage bins are to be filled
Trippers
These are necessary when material being conveyed is damp or sticky
Belt scrapers or cleaners
This cleaner is for belts in which the material is dry and not likely to stick to belt surface
Rotary brush - 450rpm rotates opposite of belt travel
These pulleys are used in conditions where tramp iron may have fallen into the belt
Magnetic pulleys
Inclined conveyors require these
Backstops
Decline conveyors require these
Brakes (mechanical, eddy-current, plugging, dynamic, regenerative)
Arc of contact in single drives
180 with no snub, 190-240 with snub
In this drive one motor drives both pulleys
Tandem drive - arc of contact 360-420
In this drive two motors are used to drive the pulleys
Dual drive (second motor usually wound rotor to synchronize)
In this drive the conveyor is driven by more than one spot on the belt, each driven by a separate motor
Multiple drives - good for long conveyors with large volume
These bucket elevators operate a high speed, good for cement
Centrifugal discharge (56-90 m/min)
These bucket elevators do not scrape material out of the boot, must be loaded through a leg at and at low speeds
Continuous bucket - less than 45 m/min, not for damp material
These bucket elevators like continuous bucket design but much heavier and use double-strand heavy duty long pitch roller chain
Super-capacity - for high lifts and large capacity. 23-37 m/min. No damp material
Similar to centrifugal discharge elevators except buckets are end-mounted between two chain, attached by fixed or swivel
Positive-discharge - 37 m/min, buckets must be inverted by snub sprocket
Can handle material that may stick
The housing which through which the elevator buckets and chain travels
Casing:
Head supports head pulley, drive assembly
Boot: bottom of casing contains tail pulley, screw take-up, houses load leg or chute
Type of belt used on bucket elevator
Friction belt
Type of bucket elevator chain
SBS, S, Class C
The most versatile form of conveyor
Screw (moves material vertically and horizontally)
The two main aspects of the screw in the conveyor
type of flight (left or right hand)
pitch
These screw flights can be removed without having to remove the whole system
sectional
This screw has half the pitch and minimizes surges when feeding scales because of even discharge
Double flight - usually only needed the last few turns of the screw
These screw flights are thicker and stronger than sectional flights
Helicoid - good for grain handling
screw flight designed to handle sticky materials
ribbon
Screw flight consists of a inner and out ribbon of the opposite lay for complete mixing of materials
double flight ribbon
Screw flight has notches cut out which allows material to be mixed
Cut flight - mixes dry material at high speeds
Screw flight that allows the greatest mixing action
paddle
screw flight allows for agitation of materials useful for cooling and drying light materials
cut and folded
This pitch is one which the pitch is equal to the diameter of the flight
standard
The pitch is less than the standard pitch, prevents too much material from being drawn into the conveyor, also used on steep inclines
short
pitch designed for rapid movement of free flowing materials such as liquids
long
pitch provides uniform withdrawal of fine material along entire length of the screw
variable
pitch increases slightly as it moves along the trough. Smooth flow of materials along entire length of flight
stepped
screw creates an even draw across the opening
tapered (used in tapered troughs)
Trough that provides a dust proof conveyor when using covers
double flanged trough
The parts that carry the weight of the screw between the ends of the trough
Hangers
Screw conveyor 12H512 RH meaning
12: Diameter in inches H: helicoid flight 5: coupling diameter 5= 2-7/16 12: thickness of flight tip in 64ths of an inch. 12/64 = 3/16 RH: Right hand
Pneumatic system ideal for conveying material from several sources and moving to one main holding bin
Vacuum system (negative air pressure)
Pneumatic system that takes material from one source (inlet) and move it to any number of destinations
Pressurized system
Feeder most used for feeding material into a pneumatic conveyor
Rotary
If no dust can be vented to atmosphere this must be mounted on the discharge side of the vacuum pump
dust filter-receiver
Type of compressor used in low pressure conveying systems
Positive displacement lobe type or roots blower (12psig)
Medium-pressure conveying systems operate at this psi
15-45 psig (conveys material up to 2000ft)
type of blower or compressor used in medium-pressure
rotary blower or sliding vane compressor
High-pressure conveying systems operate at this psi
45-125 psig
types of compressors used in high-pressure
reciprocating or sliding vane (uses a receiver and blow tank)
Combination vacuum-pressure conveying systems use these to solve blow-back
two rotary feeders in tandem
In this conveying system air is allowed to flow in a rectangular duct separated by a porous medium
Air-slide gravity (unloads and aerates material in bin, used in flour mills)
Two types of roller conveyors
gravity and powered (live)
Roller conveyor used for horizontal direction or sloped
Gravity (good for loads with a strong flat bottom)
Roller conveyor good for heavy loads such as skids or pallets, not used over 10 degrees incline or decline
Chain-driven live roller
Roller conveyor driven by a belt riding between two rolls, not used over 10 degrees incline or decline
Belt-driven live roller
Roller conveyor that allows for greater incline, up to 30 degrees
Roller bed conveyors (belt riding on top of rollers, most versatile)
Short conveyors usually twice the width of the inclined conveyor. These roller conveyors are used to prevent damage to packages as they enter the inclined conveyor
Feeder roller-bed conveyor (used if inclined over 15 degrees)
These level off belts as they reach the top of the incline and provide smooth transfer from one conveyor to next
Nose-over (adjustable from 0-30 degrees)
Type of roller that has one end tapered and forces material up the taper and off the chain
Bottle roller
Rollcases are designed to move packages on a minimum of _ rolls
3 (4 if it has a soft bottom, 5 wheels on gravity conveyors)
Length of product divided by minimum number of rolls required = minimum distance between rolls
Roller conveyors use these drives on the curves
Belt drives (hydraulic on heavy duty applications)
Conveyors used for heavy or very hot bulk materials such as rock, clinker or lump material, and inclines up to 60 degrees. Steel thickness 1/4” - 3/4”
Apron (up to 30 m/min)
In these conveyors the chain itself is used as the scraper
Drag conveyor (used for moving wood chips, hog fuel, refuse, ash)
Type of hose and pipe used in slurry systems
Heavy duty wire reinforced, non-collapsible hose
Pipe has special hardened internal walls
Wire mesh belt materials
stainless steel, mild steel, zinc plated, nickel plated, teflon coated (used in food industry)
Wire mesh weave consists of right-hand spirals joined to left hand spirals by rods or crimping the ends. Easy to clean and sanitary
Equalized weave
Wire mesh weave similar to chain link fence. Used in freezers, oven etc.
Conventional weave
Food conveyor belt is a flat strip bent into a zigzag.
Flat wire belt (used where opening size is not a condition of operation)
Food conveyor belt used in circular conveyors. This belt can make left or right hand turns
Spiral belt (circular freezers)
Food conveyor belt with large rods with special links for high speed applications
Batter belting (good for french fries)
Synthetic belt used where chemical resistance is required, suitable up to 104 C (max 120 intermittently)
Polypropylene (not below 7 C)
Synthetic belt stronger than polypropylene, can operate between -46 to 93C. Good resilience and fatigue endurance
Acetal
Synthetic belt has high fatigue factor, impact strength, not as strong as polypropylene. Withstands cold applications
Polyethylene (-73-66 C meat and poultry approved)
Synthetic belt is impact resistant, will bend as opposed to breaking
Nylon
_____ belts are a lot wider than regular conveyor belts
feeder belts
These intercept the material and are located at the discharge point of the head pulley which absorbs the impact
Rock box
These belts must be hot vulcanized
steel cord (prone to longitudinal tears)
Major cause of belt tracking problems
rollers that are jammed or stuck
____ pulleys should never be adjusted to correct belt misalignment
Head
This fastener is suitable for small repairs or tears in belt
double plate
These function the same as air receivers
Blow-tanks
In this conveyor air is allowed to flow in a rectangular duct. The material is separated by a porous medium
Air-slide gravity conveyor
What fan is used when material must pass through it
Open-faced
A special design roller that moves material at right angles to the table as the rolls rise above the chain
Eccentric roller
Roller used for turns in the conveyor bed
Tapered
Most efficient roller for turning curves
Typical tapered roll
This chain conveyor the top and bottom chain are as close to parallel as possible, the return side is tight as possible
Parallel Strand conveyor (conveying strand can be top or bottom chain depending on design)
This chain conveyor is on a slope and drive sprocket is at least 4 feet from the floor. Drive sprocket is on return side of head drum
Gravity Drop drive
This chain conveyor is used when long heavily loaded conveyors are required. This drive allows maximum number of drive teeth on the sprocket
S drives (can be used with almost any type of chain)
Chain consists of cast steel block or barrel with two cast side plates. Chain used in rough, dirty environments
combination chain
Chain is one-piece cast malleable iron with side bars offset from the barrel
Pintle and H class mill chain (400 and 700 class) H class heavier construction, wearing shoes cast on bottom used in pulp and paper
Chain is one piece casting with large pitches of 5-12 inches. Links usually made of malleable iron, manganese
Drag or refuse chain
This chain is used when material is conveyed at 90 degrees to it, comes in rooftop and roller top designs
Transfer chain (camelback)
This sprocket has either 5 or 7 teeth
Long link chain (star sprocket)
screw conveyor couplings are also known as
gudgeon shafts
Which end is the trust bearing on screw conveyor located
at the discharge end of conveyor
What do frame-supported roller apron conveyors withstand
temps up to 1100 C
The amount of drop per unit length a roller conveyor requires in order to carry the given loads is called
conveyor pitch (typical 1/4 to 1/2” per foot)
These roller conveyor drives use a hold down plate to keep chain in contact with sprockets. Used for medium loads
Continuous chain drive (does not start and stop frequently)
These roller conveyor drives have two sprockets on each shaft. Used for heavy loads
Roll to roll drive (frequent starts and stops)
____ are roller or wheel conveyors used to transfer loads off of or onto belt or roller conveyors
spurs (30 degrees max)
______ are moveable arms or plates used to sort packages in a roller conveyor system
deflectors
These are used when work is to be performed inside of a hopper or silo
isolation or blanking gates
These gates prevent pressurization of the feed hopper
air locks
On belt driven rollers the ____ race turns, on chain driven belts the _____ race turns
Belt: outer (shaft does not turn)
Chain: inner (shaft turns)
These allow the belt to run smoothly over a series of low-friction impact absorbing rubber slats
slider belt cradles
Chain that is stronger and more accurately made than cast chains
Fabricated chain
Chain that requires no tools to assemble or disassemble
Detachable chain (slow speed one direction)
How far should you overlap belts for lap joints
at least one belt width
When a wheel conveyor has wheels along the outside frame or rail only the frame is called
wheel rail section or skid assembly
The frame that supports the rollers is called the
rollcase
roller conveyor that have the tops of the rollers or wheels above the side frames
high mounted
roller conveyor that have the rollers or wheels mounted with their tops below the sides
low mounted
These are also called differential roller curves
double lane curves
These three sheaves are used when roller conveyors drive around curves
drive sheave
take up sheave
tail sheave
flat belt conveyors have a _______ drive arrangement
non-positive
these belts make a 90 degree twist to match the roller
round belts
These drives cannot be stopped without shutting off the drive unit
positive drive system
These rolls move objects sideways across the roll after reaching an end stop
spiral rolls
These rolls are used when the packages must be lined up against one side
angled rolls
rolls designed to carry cylindrical objects like pipe or logs
hourglass rolls
These pivot a short moveable section of live roller conveyor to sort packages from a main conveyor to two or three conveyors downstream
two and three-way switches
These can be vertically or horizontally pivoting and can be used to open an alley through a roller conveyor
hinged gates
these are used where several roller conveyors meet
ball transfer tables
these transfer a product 90 degrees from the initial direction of product
rotating turntables
These troughing idlers are used where overhead space is limited
off-set centre roll
Two types of wear strips for conveyors in food handling
straight parallel - light loads
chevron style - heavy loads
